JPH06148981A - Automatic document feeder - Google Patents

Abstract

PURPOSE:To provide a compact automatic document feeder where the recirculating, ejecting and reversing operation of a one-side or both-side document is made sure and stabilized, jamming processing is facilitated and quickened, and a large-sized document can be placed in an upper feeding and bottom restoring system automatic recirculating document feeder. CONSTITUTION:This automatic document feeder is provided with a 1st path for feeding the document on a document placing part 310 and supplying it to an image read part, a 2nd path approximating to the image read part, and for restoring the document to the image read part again after reversing the front or back surface of the document, a 3rd path for restoring the document from the image read part to the document placing part 310 after reversing the front or back surface of the document, a 4th path for restoring the document to the document placing part 310 from the image read part without reversing the front or back surface of the document, a paper ejection tray 360 for stacking the document ejected from the image read part to the outside of a machine, a 5th path for ejecting the document from the image read part to a paper ejecting pan after reversing the front or back surface of the document, and a 6th path for ejecting the document to the paper ejection tray 360 without reversing the front or the back surface of the document.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a recording apparatus such as an electrophotographic copying machine or an automatic document feeder in an image reading apparatus, and more particularly to a single-sided or double-sided recording original loaded on an original placing portion. Separate the sheets and feed them to the image reading unit,
ADF mode, which discharges the scanned originals to the output tray,
Circulation having an R-ADF mode or a single-sided document circulation transport mode (RDH mode) and a double-sided document reversing circulation transport mode (R-RDH mode) which are capable of returning the scanned document to the document stacking section and feeding it again. The present invention relates to a type automatic document feeder.

[0002]

BACKGROUND OF THE INVENTION As a device capable of efficiently feeding an image-recorded document to a recording device such as an electrophotographic copying machine or a recorded image reading device, even in an unmanned state, an automated document conveying device ( ADF) has already been provided.

Further, as a copying machine capable of copying each image of an original (double-sided original) having recorded images on the front and back sides and one side or both sides of the recording paper, and an image reading device capable of reading and recording the images, the ADF is provided with front and back sides of the original. An automatic document feeder (R-ADF) equipped with a reversing function has been put into practical use.

Further, the originals stacked on the original placing portion are separated one by one and automatically fed on the platen glass of the copying machine, and the originals after the exposure processing on the platen glass are again placed on the original placing portion. A circulating automatic document feeder (RDH) that can be returned and repeatedly processed has also been proposed.

This circulating automatic document feeder (RDH)
Makes copies one by one in one cycle, and circulates the original for the number of copies.

Further, recently, the present applicant has also provided a circulating automatic document feeder (R-RDH) in which a document front and back surface reversing mechanism is added to the above RDH (Japanese Patent Application No. 63-20228).

These circulating automatic document feeders (RDH,
R-RDH (hereinafter referred to as RDH device) enables high-speed continuous copying and quick page alignment of copied recording paper, and is connected to a finisher device for stapling and punching the recording paper for recording and final processing. Can be completed unattended.

In such an RDH apparatus, a plurality of originals, which are stacked with the front side of the originals facing upward on the original placing section, are fed one by one from the lowermost layer to the processing section (platen glass surface) in the feeding section. It is a bottom feed top return system that separates and conveys toward the bottom.

In such a bottom feed top return type RDH device, when the documents are fed out, problems such as the disorder of the document image due to the smearing or rubbing of the document front and back surfaces caused by the friction between the document front and back surfaces occur. In particular, in the case of a pencil-written manuscript, the manuscript stains due to the above problems are remarkable.

As a means for solving the above problem, Japanese Patent Publication No. 56
The top feed / bottom restack type RDH device disclosed in Japanese Patent No. 37536 has been proposed. In this method, the processed sheet is inserted from the lower side of the stack sheet by the cyclically moving stack lifting means for lifting the sheet.

The sheet storing and feeding apparatus disclosed in Japanese Patent Laid-Open No. 3-205273 discloses a sheet feeding and feeding apparatus for an RDH apparatus. The vertical pressing member is arranged at the position. Further, Japanese Laid-Open Patent Publication Nos. 4-16671 and 4-116672 relate to the reverse document feeding direction, and a direction changing pawl is provided at a branch position for forward rotation and reverse rotation to switch the path.

[0012]

The top feed / bottom restack type RDH apparatus has the following problems.

The structure of the periodic movement type lifting means for lifting the stack becomes complicated.

If there is a curl at the leading edge of the sheet inserted from the lower side of the stack, there is a high possibility that the cyclic lifting type stack lifting means will be caught.

When the sheet returning speed becomes high, the operation of the document feeding apparatus becomes complicated, and there is a high possibility that the sheet becomes unstable.

Since the stack lifting means moves up and down every time the sheet returns, noise is generated due to the up and down movement of the sheet.

When the sheet size is different, it is difficult to deal with each size.

The invention of Japanese Patent Application No. Hei 2-403220 by the applicant of the present invention, which solves the above-mentioned problems, is an upper feed bottom return type circulating type automatic document feeder, which feeds a document by means of an upper suction fan means and a feeding belt. And a document returning / rotating means by a plurality of lower narrow belts.

However, the automatic document feeder having this structure has the following problems and further improvement is required.

(1) The suction fan means emits noise and increases the manufacturing cost.

(2) In a structure in which a plurality of narrow belts are arranged, the originals placed on the respective belts and returned to the bottom do not stick to each other because there is a gap between the belts, and the originals are wavy along the solid traveling direction. Upon contact, the projecting portion at the leading edge of the original document may collide with the rear end portion of the upper original stack, causing an original document jam.

[0022]

SUMMARY OF THE INVENTION The present invention solves various problems in the conventional automatic document feeder as described above, is stable even during a high speed feeding operation, and can cope with various document sizes. An object of the present invention is to provide a feed / bottom insertion type circulating automatic document feeder.

In particular, an object of the present invention is to read a plurality of originals as an image by making a conveyance interval between a preceding original and a succeeding original as short as possible by a simple structure and control and further preliminarily feeding the originals. An object of the present invention is to provide an automatic document feeder that can shorten the copying time by significantly shortening the time required to carry the sheet to another section.

In the automatic document feeder of the present invention which achieves the above object, one of at least one set of a plurality of documents stacked on the document placing section is separated and fed to the image reading section. And a second feeding unit which is located on the upstream side of the document transportation of the image reading unit, reversely feeds the document from the image reading unit, reverses the front and back, and returns to the image reading unit again. A feeding unit, a feeding unit that conveys the document fed to the image reading unit and stops it at a predetermined image reading position, and conveys and carries out the document after the image reading, and a position downstream from the image reading unit First circulating means for returning the document carried out from the carrying means to the document placing section with the same side as the upper surface at the start of feeding up, and the document carried out from the carrying means to the image reading section. Second circulation means for returning the side opposite to the upper surface at the start of feeding with the side up and the image reading The carry-out is a document of the outside of the machine from 1
A first sheet discharging unit for discharging the document reading surface of the image reading unit downward on the sheet discharging tray, and a document discharged from the image reading unit is temporarily stored in a second sheet discharging tray outside the machine. After discharging, the original is fed back, and the original is turned upside down via the paper discharge path and is discharged to the first paper discharge tray.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the automatic document feeder according to 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 an automatic document feeder. 100 is a copying machine main body, 200 is a paper feed unit (PFU device), and 300 is a circulation type automatic document feeder (RDH device). ), 400 is a copying paper post-processing device (finisher (sorter with stapler device, etc.) hereafter referred to as FNS device).

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

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

FIG. 2 is a sectional view of the automatic document feeder 300 mounted on the upper portion of the copying machine main body 100. The automatic document feeder 300 to which the present invention is applicable conveys a plurality of originals (single-sided original or double-sided original) from the original placing section 310 to the exposure section of the platen glass 111 of the copying machine main body 100,
It is provided with various functions such as a circulation type RDH device, an R-RDH device, an ADF device, an R-ADF device, etc., which conveys again onto the document placing section 310.

The automatic document feeder 300 includes a document placing section 310,
Feeding unit 320, intermediate conveying unit 330, conveying unit 340, paper discharge reversing unit 350
It consists of

When the original stack D is placed on the original placing section 310, the presence or absence of the original is detected by the original set detection sensor (zero original detection sensor) S1, and the ADF mode is displayed on the control panel of the copying machine main body 100. Is displayed. When the document stack D is set at a predetermined position, the document size (B5 to A3) is detected by the document size sensor S2 and input to the control unit of the copying machine main body 100.

A movable pressing plate 317 is swingable around a swing shaft 317A at the leading end side of the document feeding portion 310 on the downstream side of document feeding. A drive plate 319 is screwed to the swing shaft 317A so that it can swing integrally. Further, an elastically deformable member (for example, a torsion spring) 317 is attached to the swing shaft 317A.
B is wound, and the drive plate 319 can be pressed at both ends thereof and the movable pressing plate 317 can be pressed at the center thereof.

The actuator portion provided on the drive plate 319 includes a pressing home position sensor S fixed to a fixed bottom plate.
The optical path of 3 is turned on and off, and the home position of the drive plate 319 is detected.

FIG. 3 is a perspective view of an essential part of the document placing section 310. The wide feeding belt 311 which is loaded with the document D and supported and is rotatable is an endless belt wound around two axes of a driving roller 312A and a driven roller 312B.

FIG. 4 is a perspective view of the feeding belt 311. One end of the feeding belt 311 is joined by a joint 311A to form a loop. The other end of the belt 311 forms a tongue-shaped holding piece portion (gripper portion) 311B extending outward from the seam portion 311A. The feeding belt 311 is formed of a cloth belt coated with resin, a polyethylene terephthalate (PET) film, or the like. The feeding belt 311 is roughened to have a friction coefficient, and the other belt outer surface (between B and C in FIG. 4) is a smooth surface having a low friction coefficient. 311C is a detection hole formed in a part of the belt 311, and the home position of the feeding belt 311 is detected by the reflective sensor S13 for detecting the home position of the feeding belt, and the feeding belt 311C is detected. The stop position of the sandwiching piece 311B of 311 is controlled.

In FIG. 3, an electromagnetic brake BRK2 and an electromagnetic clutch CL4 connected to a paper discharge motor M3 as a drive source are provided at the end of the rotary shaft of the drive roller 312A. A fixed plate 313 is fixedly provided inside the feeding belt 311 between the drive roller 312A and the driven roller 312B. The fixed plate
313 supports the document bundle D on the feeding belt 311 by placing it on a flat surface.

Denoting means 315 separates the lowermost sheet of the original bundle stacked on the feeding belt 311 from the uppermost sheet of the original bundle that is circulated after the reading process and placed at the bottom of the lowermost stack of the stacked originals. Is. The separating lever 315A of the separating means 315 is spring-biased, and the solenoids SL3, S
L4 is used for ascending / descending, forward / backward and obliquely descending drive in the direction orthogonal to the sheet feeding.

In 311D, the separating lever 315A is a feeding belt.
Feed belt 3 to allow it to rise above 311
It is a notch provided on the side of 11.

The original stack placed on the original placing section 310 is stacked on the feeding belt 311 and a movable pressing plate 317, which will be described later, and the width stopper plate 316 that restricts the original stack in the original width direction by one side base. At the same time, the leading edge of the original is brought into contact with an original leading end stopper 318, which will be described later, and aligned and placed. At this time, the separating lever 315A is pressed and lowered by the weight of the document stack, and lightly pushes up the lowermost layer of the document stack. Further, the swingable paper pressing lever 310Z provided on the upstream side of the separating lever 315A in the document conveying direction is for assisting the returning document to be surely inserted under the document stack, and the document surface is supported by its own weight. Lightly press. The paper pressing lever 310Z is also effective for stabilizing the operation of the separating lever 315A when carrying curled paper or a small number of originals.

FIG. 5 is a front sectional view of the document placing section 310 and the feeding section 320, and FIG. 6 is a side view of the separating means 315 and the separating lever pushing means (hereinafter referred to as pushing means) 314. In these drawings, one fixed side plate 31 that pivotally supports a driving roller 312A and a driven roller 312B that rotate the feeding belt 311.
At 0A, a separating means 315 and a pushing up means 314 are fixed. That is, near the one side end of the feeding belt 311, the pushing-up means 314 is fixed on the upstream side in the feeding direction, and the separating means 315 is fixed on the downstream side in the arrow direction.

A solenoid SL3 is fixed to the lower part of the substrate 315B of the separating means 315, and the solenoid SL3 is fixed.
The lower end of the swing lever 315C is pin-connected to one end of the plunger SL3A. The swing lever 315C is provided on the substrate 3
It can swing around a fulcrum shaft 315D planted in 15B and is urged in one direction by a spring 315E. The upper end of the swing lever 315C has a separating lever 315A and a pin 315F.
Are bound by. Separation lever 315A has pin 315F
The weight 31 that can be swung around is fixed to the left end.
Due to the 5G's own weight, the left end part hangs down and can be tilted when no regulatory force is applied.

A pin 315H is provided in the middle of the separating lever 315A.
And is movable along the wall surface of the D-shaped cam groove portion 315J formed in the substrate 315B. 315K is a boat-shaped leaf spring attached to the base plate 315B, and is in sliding contact with the upper surface of the separating lever 315A to form a separating lever 315A.
Will be the guide surface for horizontal movement.

A solenoid SL4 is fixed to the lower portion of the base plate 314B of the separating lever pushing-up means 314, and a swing lever 314 is provided at one end of a plunger SL4A of the solenoid SL4.
One end of C is pin-connected. The swing lever 314C is swingable around a fulcrum shaft 314D planted on the upper portion of the substrate 314B, and is biased in one direction by a spring. The other end of the rocking lever 314C is provided with a long rod-shaped push-up lever 3
The base of 14A is driven in and the tip projects. The push-up lever 314A is in contact with the lower surface of the separating lever 315A in the vicinity of the front end thereof and is held so as to be able to move up and down.

In the initial unloaded state in which the original stack is not placed on the feeding belt 311 of the original placing portion 310, the separating lever 315A is tilted by the weight of the weight 315G and the right end portion is raised. It has become (position of Figure 6). Then, the pin 315H reaches the top dead center of the cam groove portion 315J and is positionally regulated and stopped. At the raised position of the separating lever 315A, the copy number separating sensor S14 is turned off.

When the bundle of documents D is stacked on the feeding belt 311 of the document placing portion 310 and the leading end of the separating lever 315A is lowered by the weight of the document stack D, the pin 315H of the separating lever 315A has a cam groove portion. It descends along 315J and is in light contact with the bottom sheet of the document stack. (Position shown). In this descending state of the separating lever 315A, the copy number separating sensor S14 is turned on. At this time, the front end of the paper pressing lever 310Z presses the upper surface of the document stack by its own weight.

As the document stack on the document mounting table 310 is fed upward and returned to the bottom, the leading end of the separating lever 315A is sandwiched between the last page of the stack of document stacks and the first page of the returned document. As the number of returned documents increases, it gradually rises (the position shown), and when the first page of the returned document reaches the uppermost position, it becomes free and jumps up into the upper space (the position shown). At this time, the copy number sensor S14 is turned off.

The separating lever 315A is a solenoid SL.
The suction operation of 3 draws it to the left in the drawing (the position shown). When a voltage is applied to the solenoid SL3, the plunger SL3A is attracted and the swing lever 315C is swung in the counterclockwise direction indicated by the arrow about the fulcrum shaft 315D, and the pin 3
The separator lever 315A connected by 15F is moved to the left. The pin 315H implanted in the separating lever 315A is
It moves diagonally downward in the cam groove 315J, and the cam groove 315J
Stops the movement by contacting the left end of the. At this time, the leaf spring 315
K slides on the upper surface of the separating lever 315A to prevent the separating lever 315A from jumping upward.

When the energization of the solenoid SL3 is turned off after a predetermined time, the swing lever 315c moves to the fulcrum 31 by the spring 315E.
Rotate clockwise around 5D to move the lever 315A to the right (position shown in the figure). At this time, leaf spring 315K
Keeps the lever 315A horizontally, the pin 315H
The sheet moves to the right and the leading end of the cutout portion 311D of the sheet feeding belt 311 enters and rises by its own weight to rotate and come into contact with the lower surface of the original.

A notch 311D is formed at one end of the feeding belt 311 so that the separating lever 315A can be retracted below the feeding belt 311. When the document bundle is stacked on the feeding belt 311 and rotated, the cutout portion 311D may collide with the lower layer of the document bundle to cause conveyance failure. To prevent this, before the cutout portion 311D passes upstream of the document stack in the document transport direction, one end of the document stack is pushed upward so as not to interfere with the feeding belt 311 and at the same time, the document is separated. Make sure that the tip of the lever 315A is returned and that it is inserted above the document. In other words, when the first document after the exposure processing is discharged and returned to the bottom of the document stack on the feeding belt 311 of the document placing section 310, the nip portion 311B of the rotating feeding belt 311 is used. Leading notch 31
The separating lever 315A is always located above 1D, and the separating lever 315A is raised by a predetermined amount so that the separating lever 315A is surely located above the feeding belt 311, and the relevant portion of the document stack is retracted upward. deep. Therefore, the solenoid SL4 is actuated by the signal for document replacement, and the plunger S
L4A is sucked, the swing lever 314C is swung about the fulcrum shaft 314D, and the push-up lever 314A is raised. When the push-up lever 314A swings, the corresponding separation lever 315A is lifted upward by a predetermined amount and stopped. As a result, one end of the document stack of the separating lever 315A is lifted upward so that the separating belt 315A can pass through the notch portion 311D of the feeding belt 311 and at the same time, the returning document is surely separated.
Guide below 5A.

As shown in FIGS. 2 and 3, on the downstream side of the feeding belt 311 in the document feeding direction, movable pressing plates 317 of movable pressing means are provided on both side plates which are integrated with the fixed bottom plate 310A. A drive plate 319 is screwed to a swing shaft 317A supported by a bearing so that it can swing integrally. An elastically deformable member (for example, a torsion spring) 317B is wound around the swing shaft 317A, and both ends of the elastically deformable member 317B are pressed against the drive plate 319 and the movable pressing plate 317 to bias the spring.
At this time, the movable pressing plate 317 and the drive plate 319 are pushed in the opening direction of the torsion spring 317B, but the lower end portion of the movable pressing plate 317 abuts one end of the drive plate 319 and the opening angle between them is a certain amount or more. It is regulated not to open. The spring pressure of the torsion spring 317B is adjusted to the set pressure.

An actuator portion (light shield plate portion) 319A projects from one end of the swing shaft 317A. The actuator portion 319A includes a pressing home position sensor (for example, a photo interrupter) S3 fixed to the fixed bottom plate 310A.
The optical position of the drive plate 319 is turned on and off, and the home position of the drive plate 319 is detected. It can swing around the swing shaft 317A. A gear is fixed to one shaft end of the swing shaft 317A and is connected to the gear fixed to the drive shaft of the pressing motor M1.

A document end stopper 318 is fixed to the main body of the automatic document feeder near the leading end of the movable pressing plate 317 on the downstream side of document feeding.

Above the movable pressing plate 317, a feeding section 320 is provided.
Is provided. The feeding unit 320 includes a feeding roller 321.
A driving roller 323, a driven roller 322, a feed belt 324 that winds and rotates both rollers, and a double feed preventing reverse roller 325 located below the feed belt 324. The driving force of the driving motor M2 is transmitted to the driving roller 322 via the electromagnetic clutch CL1.

Frame body 321 holding the delivery roller 321
A is swingable around a support shaft A. The frame 321A
The actuator part 321 protruding at the tip of the
B is integrally formed and turns on / off the detection optical path of the pressure detection sensor S4 fixed at a predetermined position of the fixed stay member 300A of the automatic document feeder 300.

FIG. 7 is a schematic diagram showing the conveyance state of the document D discharged from the sheet discharge reversing unit 350 to the feeding belt 311 of the document placing unit 310 and the movable pressing plate 317.

After a lapse of a predetermined time (the front end of the original comes close to the holding piece portion 311B) after the front end of the original is detected by the paper discharge sensor S9, the clutch is engaged and the holding piece of the feeding belt 311 starts rotating from the home position. When the leading edge of the document D is clamped by the portion 311B, the document D is clamped on the rough surface of the feeding belt 311 which further rotates, and is inserted into the lowermost layer of the stacked unprocessed document stack D to the left in the figure. Be carried to (Fig. 7 (A), (B)
reference). As described above, at this time, the separation lever 315A is
The push-up lever 314A is lifted upward through the cutout portion 311D of the sheet feeding belt 311 via the solenoid SL4 to raise the document stack by a predetermined amount.

At this time, the movable pressing plate 317 is in the lowered position, and the leading end of the document stack D is separated from the feed roller 321. The surface linear velocity of the feeding belt 311 is set to be slightly higher than or equal to the surface linear velocity of the circulation paper discharge roller (deviation correction roller) 355 of the paper discharge reversing unit 350 (for example, D-3 speed 1000 mms. About 1150 mm / s for / s). Also,
Since the surface of the feeding belt 311 that comes into contact with the document D is a rough surface, the document D is reliably held by the feeding belt 311 and fed.

Furthermore, since the surface of the feeding belt 311 that contacts the lowermost layer of the document stack D is a smooth surface, the feeding belt 311 smoothly rotates in sliding contact with the lower surface of the document stack.

Document D held on the feeding belt 311
Is slid on the upper surface of the movable pressing plate 317 slightly below the upper surface of the feeding belt 311 as the feeding belt 311 is turned downward along the driven roller 312B, and hits the document leading edge stopper 318. , Feeding stops. Therefore, if the entire circumference of the feeding belt 311 is set to be equal to or greater than the maximum length of the document D being circulated and conveyed in the feeding direction, the document returning operation is good.

Referring again to FIG. 2, an intermediate conveying section 330 is provided on the downstream side of the original conveying with respect to the feeding section 320. The intermediate conveying section 330 includes a first intermediate conveying roller pair 3 which is driven to rotate forward.
31, a curved guide plate 332, and a pair of second intermediate conveying rollers 333 form a conveying path for conveying the document D sent from the feeding unit 320 to one end of the platen glass 111.

Further, a reversing means is provided on the left side of the second intermediate conveying roller pair 333 and on the left side of the platen glass 111 in the drawing. The pair of reverse conveyance rollers 335 is always driven to rotate normally by the one-way clutch CL5. A curved guide plate 336 connects the nip positions of the second intermediate conveyance roller pair 333 and the reversal conveyance roller pair 335, and forms a document reversal feed path. A reversal detection sensor is provided in a part of the reversal feed path, and detects passage of a reversal fed document.

On the surface of the platen glass 111, a conveyor belt 341 is rotatably stretched between a driving roller 342, a driven roller 343, four document pressing rollers 344 and a tension roller 345. A clutch and a brake are rotatably supported on the shaft of the drive roller 342.
Is operated by the driving force of the drive motor M2.

The paper discharge reversing unit 350 includes the paper discharge rollers 351, 352,
Switching claws 353, 357, reversing conveyance roller 354, circulation discharge roller 3
55 and guide plates 356A, 356B, 356C and the like. The paper discharge rollers 351, 352, the reverse paper discharge roller 354, and the circulation paper discharge roller 355 are driven by the paper discharge motor M3. The paper discharge roller 352 and the circulation paper discharge roller 355 are driven to rotate in the forward direction by a paper discharge motor M3, and the reverse conveyance rollers 351 and 3 are provided.
54 is driven in forward / reverse rotation, and the discharge rollers 355 and 352 are always driven in forward rotation. The switching claw 353 is driven by the switching solenoid SL1. The switching claw 357 is driven by the switching solenoid SL2.

On the upper part of the copying machine main body 100, a discharge tray section 360 is fixedly provided near the discharge opening of the discharge reversing section 350 of the automatic document feeder 300. The paper output tray unit 360 is
A fixed tray 361 having an inclined surface fixed to the upper surface of the casing of the copying machine main body 100 by a screw or the like, and a movable tray (a resin tray) pivotally supported by a fulcrum shaft 362 provided at one end of the fixed tray 361. ) And 363. In the folded state of the movable tray 363, a reverse discharge path 364 is formed between the inclined upper surface of the fixed tray 361 and the inclined lower surface of the movable tray 363 with a constant space. The document D sent from the reversing and discharging roller 354 is moved up the reversing and discharging path 364, the sensor S11 detects the trailing edge of the document, and after a predetermined period of time, the document D is temporarily stopped, and then the reversing and discharging roller 354 is operated. By reverse rotation drive, it is introduced into the automatic document feeder 300,
In the RADF mode of a double-sided original, it is ejected out of the machine by the ejection roller 352 of the ejection reversing unit 350, passing through the guide 356C.
It is placed on the upper surface of the movable tray 363.

When the movable tray 363 of the paper discharge tray section 360 is rotated and unfolded, the upper surface of the fixed tray 361,
Large originals such as A2 size paper and fanfold paper (CFF) can be discharged to the lower surface side of the movable tray 363.

In addition, the reverse circulation mode (R-R
At the time of DH), the switching claw 357 is switched to the lower side, and the document D conveyed to the above-mentioned reverse discharge path 364 passes through the reverse discharge roller 354, the guide plates 356C and 356B, and the circulation discharge roller 355, and is placed on the document. Returned to part 310.

FIG. 8, FIG. 9 and FIG. 10 are schematic diagrams showing the document transport path (dotted line) in various modes.

FIG. 8A shows an ADF mode in which a one-sided original is copied and discharged to the discharge tray section 360 outside the machine. The original D is transferred from the original placing section 310 to the first conveyance path a, b. , C,
In the case of a general document of A3 size or smaller, it is placed and accommodated on the movable tray 363 from d, e through the fifth conveyance paths f, g, h. In the case of a large-sized document (A2, fanfold paper, etc.), it is placed and accommodated over two surfaces connecting the fixed tray 361 and the movable tray 363.

FIG. 8B shows an R-ADF mode in which a double-sided original is copied and discharged to the discharge tray section 360 outside the machine. The original D is first conveyed in the first conveyance paths a, b, c, d and After exposing the first surface of the original through e, the platen glass 111 is moved backward and the loop path (second conveyance path) i is turned upside down and the path is passed again through the path d. Then, the second surface of the original is exposed through e. The document D that has been subjected to the double-sided exposure processing is carried out to the reversal paper discharge unit 350, passes through the paths f, j, and k, enters the tunnel-shaped reversal paper discharge passage 364 of the paper discharge tray unit 360, and then reverses. The paper is sent and is placed and accommodated on the movable tray 363 of the paper discharge tray unit 360 via the sixth conveyance paths m and h.

FIG. 9C is a schematic view of the RDH mode showing the circulation circulation of a single-sided original and a single-sided copy. The one-sided document D is fed in a progressive circulation path (first conveyance path) a, b, c,
After the exposure process through d and e, the path of the sheet discharge reversing unit 350 (the third
Of the feeding belt 311 of the original placing portion 310 through the holding piece portion 311B of the feeding belt 311.
The document is conveyed to the bottom of the original stack and returned to the bottom.

FIG. 9 (D) is a schematic diagram of the R-RDH mode showing the circulation of documents during double-sided copy and double-sided copy. The path to the exposure process for the odd-numbered side of a two-sided original is
Same as the mode, one side copied sheets are stacked in ADU 180. Further, the original is sent again through the feeding paths (first conveying paths) a, b, c, d,
When the trailing edge of the document passes through the roller pair 334 and the sensor S7, the transport belt 341 is rotated in the reverse direction, and after passing the (second transport path) i, the other surface of the document is exposed at e and the fourth transport path f, j. , K, switch back, and are returned to the original placing section 310 in the original direction via m, n. In accordance with this operation, a sheet having an image on one side is sent out from the ADU 180, and the image is received on the other side, and a two-sided copy in which the page order is aligned is created. That is, the operation of copying only one side in the first cycle and the operation of copying the other side in the second cycle to make one copy are repeated by the designated number of copies.

FIG. 10 (E) is a schematic diagram showing a process of transporting CFF paper in a mode for copying fanfold paper for computer output (CFF paper). In this mode, the automatic document feeder 300 is opened and the CFF paper is set on the platen glass 111 with the right end of the 111 as a reference, and then the automatic document feeder 300 is closed to set the transport belt 341.
The CFF paper is conveyed by (path p → e). S18 (Fig. 11
Reference numeral) is a sensor for detecting the perforation hole of the CFF paper, and controls the transport stop position of the CFF paper. The CFF paper conveyed to the paper discharge reversing unit 350 by the switching claw 353 switched in advance is discharged to the outside of the machine via the paths f, j, and k, and the discharge tray unit 360 in the pre-expanded state is fixed. The sheet is conveyed along the tray 361 and the movable tray 363, and placed below the discharge tray.

FIG. 11 is a block diagram showing the drive system (power transmission system) of the automatic document feeder 300, and FIG. 12 is a block diagram of the drive system. The CPU controls all the operations.

The document conveying operation in various modes will be described below.

(A) ADF mode (small-sized single-sided original) (A1) Feed belt 311 of movable plate 310 and movable pressing plate
When the document stack D is placed on 317, the set detection sensor S1
Turns on and enters ADF mode. At the same time, the size detection sensor S2 is turned on, and the document size is detected. A detection signal from the sensor S2 is sent to the control unit by a small-sized original (B5 size, A4 size, 8.5 × 11 inch letter size,
8.5 × 14 inches legal size, etc.) will be switched to the small size mode.

FIG. 13 is a time chart showing the conveying operation of the small size original document. FIG. 14 is a schematic diagram showing a process of conveying a plurality of originals.

(A2) When the copy button is turned on, automatic document feeding and copying can be started, the pressing motor (stepping motor) M1 starts driving rotation, and the swing shaft 31
The movable pressing plate 317 swings and rotates via a drive plate 319 fixed to 7A and a spring 317B, the tip of the movable pressing plate 317 rises, and the stacked document stack is lifted. In this ascending process, the swing shaft 317
The swing angle of A is detected by counting the number of pulses generated from the rotary encoder, for example.

(A3) When the upper surface of the document bundle D stacked on the movable pressing plate 317 is pressed against the outer peripheral surface of the feed roller 321, the feed roller 321 is swung upward around the fulcrum A, When the pressure detection sensor S4 is turned on and the feeding roller 321 further rises, the feeding roller 321 and the movable pressing plate 317 stop raising by coming into pressure contact with a fixed plate (not shown). The movable pressing plate 317 stops while holding the document stack, but the drive plate 319 is further driven and rotated to rotate the counterclockwise direction while compressing the torsion spring 317B.
When the distance between the movable pressing plate 317 and the driving plate 319 is narrowed and the pressing detection sensor S4 is turned on, the encoder starts counting. Then, after a predetermined count, the pressing motor M1 stops driving. As a result, a pressing force corresponding to the sum of the self-weight of the feed roller 321 (for example, 50 g) and the spring force (for example, 70 g) wound by a predetermined pulse is generated to clamp the document stack. Therefore, it is possible to freely set the pressing force by changing the predetermined pulse amount.

With the above operation, the preparation for feeding the original is completed,
The document feeding continues.

(A4) When the pressing operation is completed, the drive motor (main motor) M2 is turned on, and at the same time, the electromagnetic clutch CL1 is turned on and document feeding is started. That is, the upper layer original document is sent out by the feed belt 324 which starts to rotate by the driving force of the drive motor M2 rotated at a low speed, and further, the uppermost original document D1 among the plurality of original documents sent out by the reverse roller 325. Only the sheets are separated and sent.

One sheet of the document D1 separated and fed as described above.
Is detected by the bending correction sensor S5, the drive motor M2 is turned off after a lapse of a predetermined time (timer T1) from the generation of the tip detection signal, and the registration clutch CL2 is reached.
Is turned off and hits the stopped first intermediate conveyance roller pair 331, and the feeding bend of the document D1 is corrected.

Further, after the elapse of a predetermined time by the timer T2, the drive motor M2 is re-driven and rotated. At this time, the drive motor M2 is rotated at a high speed, the registration clutch CL2 and the transport clutch CL3 are turned on simultaneously with the delivery clutch CL1, and the document D1 is transported downstream.

The leading edge of the document D1 is the document passage detection sensor S5.
Crossing over the clutch C that was driving the drive roller 323.
L1 is turned off, and the feed belt 324 is driven to rotate until the trailing edge of the document D1 passes through the sensor S5 and then stops, but the document D1 is continuously conveyed by the first intermediate conveyance roller pair 331.

Next, the leading edge of the document D1 is the registration sensor S.
When the signal passes through 7 and the signal is turned on, counting is started by the drive roller 342 of the conveyor belt 341 and the encoder sensor S16 (encoder 1) for the encoder plate directly connected to the second intermediate conveyor roller pair 333. After the predetermined count by the encoder 1, the drive motor M2 and the registration clutch CL2 are turned off. Further, at this time, the encoder 2 starts counting, and after a predetermined count, the transport clutch CL3 is turned off,
The transport brake BRK1 is turned on and the rotation of the transport belt 341 and the third intermediate transport roller pair 334 is stopped.

When the document passage detection sensor S5 is turned on, the pressing motor M1 is switched to the reverse rotation,
The drive plate 319 and the movable pressing plate 317 are lowered to release the pressing.

When the drive plate 319 returns to the initial position,
When the home position detection sensor S3 detects it, the pressing motor M1 is stopped. Alternatively, when a plurality of originals are continuously fed, the driving plate 319 and the movable pressing plate 317 are not returned to the home position, and the pressing detection sensor S4 is used.
Based on the detection signal of 1) or the drive start signal in the separating direction of the drive means, the descent drive of the drive plate 319 and the movable pressing plate 317 is stopped in the middle.

The leading edge of the first original D1 is the registration sensor S.
When the detection signal is turned on after passing through 7, the pressing motor M1 starts pressing drive of the driving means based on the detection signal, and the driving plate 319 and the movable pressing plate 317 are raised to continuously press the succeeding document D2. To start.

The first original document D1 sent out by the separating / feeding means and conveyed by the first intermediate conveying roller pair (registration roller) 331 is detected by the passage detecting sensor S6 as the passage of the front end of the original document and is guided. The sheet is fed through the spaces between the plates and further between the guide plates 332.

A registration sensor S7 is provided between the conveyance section 340 and the second intermediate conveyance roller pair 333. When the registration sensor S7 detects the leading edge of the first original D1, the conveyance is performed. The first pulse counter PC1 counts the number of pulses generated by the rotary encoder RE that generates a pulse signal at each predetermined rotation angle of the drive roller 342 of the belt 341 (generates a pulse signal in accordance with the rotation of the conveyor belt 341). Start counting with.

(A5) Next, when the timer 4 counts up, the drive motor M2 is rotated at a low speed, the feed belt 324 is rotated, the succeeding document D2 is sent out, and the registration operation is similarly completed. To do. During this time, the transport belt is stopped, and the preceding document D1 is kept stopped at an intermediate position on the platen glass 111. Then, in this stopped state, the distance L1 of the leading end of the preceding document D1 and the reading stop reference is set to be a predetermined distance (for example, 236 mm). The distance from the nip position of the registration roller 331 to the leading edge of the subsequent document D2 is also set to L1 (for example, 236 mm) (see FIG. 14C).

(A6) The drive motor M2 starts to rotate at a high speed due to the count-up of the timer T6, and the registration roller 331, the intermediate roller pair 333 and the conveyor belt 341 rotate at a constant speed, and the preceding document D1 and the succeeding document D1 follow. The original document D2 is sandwiched and slid on the platen glass 111 to be conveyed.

Here, the document D is read by the registration sensor S7.
When the tip of 1 is detected, the rotary encoder R
The count number in the first encoder pulse counter PC1 that started counting E is equal to the registration sensor S
When the value corresponding to the distance from 7 to the off-timing position of the drive motor M2 is reached, the drive motor M2 is turned off.

Further, from the stop of the drive motor M2 to the motor M
2 decelerates due to inertia, and when the number of pulses counted by the second pulse counter PC2 for counting the pulses of the rotary encoder RE reaches a predetermined value, the operation of the brake BRK1 is started at the same time when the conveyance clutch CL3 is turned off. To be done. Thus, the document D1 is stopped at a predetermined reading position on the platen glass 111 by stopping the drive motor M2 by the first pulse counter (1) and controlling the brake operation timing by the third pulse counter PC3 from the stop.

That is, in this embodiment, the amount of movement of the document D is managed by counting the number of pulses of the rotary encoder RE with the registration sensor S7 as a reference without using the document stopper, so that the document D is conveyed to the reading position. It is a thing.

By the way, in the case of this embodiment, the first original D
1 before stopping at the predetermined reading position, the following document D2
Passes through the registration sensor S7. It is necessary to convey the original D1 to the reading position similarly to the original D1 after the original D1, but the second pulse counter PC2 and the third pulse counter PC3 control the initial conveyance of the original D1. Therefore, the separately provided first pulse counter PC1 is reset to zero from the start of conveyance of the original D1 from the intermediate stop position and made to stand by, and the pulse of the rotary encoder 147 is pulsed from the time when it passes the registration sensor S6 of the next original D2. Start counting.

In the following conveyance control of the document to the reading position, as shown in the timing chart of FIG. 12, the first pulse counter PC1 outputs a pulse from the detection timing by the registration sensor S7 to the intermediate position. The pulse counter is switched from the first to the second at the timing of counting and starting the conveyance of the read document from the intermediate position to the reading position, and the first pulse counter is set aside for the conveyance control of the next document. Then, the offset of the drive motor M2 is controlled by the second pulse counter PC2, and further, the brake BRK1 is activated when the count number of the third pulse counter PC3 reaches a predetermined value from the off timing of the drive motor M2. repeat.

(A7) The original D1 is exposed on the platen glass 111 by the exposure lamp of the scanning exposure optical system, and an original image is formed on the photosensitive drum through the lens, the mirror and the like.

The same exposure is repeated for the set number of copies, and a series of copying processes for the original D1 is performed.

During the exposure operation, the driving motor M2 and the clutch CL1 are increased by the count-up of the timer T4.
Is activated, the feed belt 324 is started, and the next original D
3 is sent out, the registration operation is performed by the control of the timer TIM1, and the leading end of the document D3 is stopped at a position where a predetermined distance L1 is maintained from the leading end of the document D2.

Therefore, at this time, the three originals D1 to D3 are arranged in a row in a row at a predetermined interval L1 from each other on the conveying path from the separating / feeding means to the reading section.
At this time, the document D1 is placed at the reading position of the platen glass 21, and the document D2 stands by at a position that is stretched between the transport belt 141 and the second intermediate roller pair 132 (second transport roller pair). Then, the document D3 waits at the position where it hits the registration roller 331, and the documents D2 and D3 stand by in a state where the subsequent conveyance can be performed stably.

(A8) After the exposure operation of the document D1 is completed, the conveyor belt 141 is rotated by the rotational drive of the drive motor M2,
Further, the paper discharge motor M3 is rotated. Exposed original D
1 passes through the paper output reversing unit 350 and is output to the paper output tray unit 360 outside the machine. That is, the document D1 is ejected from the platen glass 111 by the conveyor belt 341, further continuously conveyed to the paper ejection roller 351, and ejected to the outside by the paper ejection roller 352 located downstream. At this time, the paper discharge motor M3 turns on the original D1.
High-speed conveyance is performed until the trailing edge of the trailing edge passes through the transport belt 341 (for example, the linear velocity of the transport belt 341 is 1000 mm / sec, the linear velocity of the discharge rollers 351 and 352 is 1200 mm / sec), and the trailing edge of the document is pulled out. , It can be switched to low speed transportation (eg 600 mm / sec). Since the paper discharge motor M3 is independent of the drive motor M2, it is possible to continue the paper discharge operation even while the subsequent document is being exposed.

In this embodiment, the document is rotated at a high speed (1000 mm / sec) for the original replacement time, and is operated so as to be switched to the low speed discharge during the exposure. In addition, the installation position of the discharge sensor S9 is set as close to the discharge position as possible. The high-speed conveyance is performed for the subsequent original replacement time, and the control is performed to decelerate before the trailing edge of the original passes through the discharge sensor S9. As a result, the deceleration operation start can be determined regardless of the installation position of the paper ejection sensor S9, and the paper ejection sensor S9 can detect a jam until the end of the paper ejection.
It can be detected by 9.

At the same time, the next original document D2 waiting on the way is slid on the platen glass 111. Here, as described above, the drive motor M2 is stopped based on the moving amount of the document D2 from the passage of the registration sensor S7 detected by using the first pulse counter PC1 and the second pulse counter PC2, and further, The operation timing of the brake BRK1 is controlled based on the count of the 3-pulse counter PC3 to stop at the predetermined reading position. Further, the succeeding document D3 is stopped at the midway standby position by the same operation as described above.

(A9) During the exposure operation of the original D2, the next original D
4 is fed and stopped at the position of the distance L1 from the leading edge of the next original D3.

(A10) After the exposure of the original document D2 is completed, the exposed original document D2 is discharged, and at the same time, the platen glass 111 is released.
The document D3, which is on standby halfway up, is transported to the exposure position, and the subsequent document D4 is kept on transport and waits at the halfway standby position while maintaining the interval L.

After that, the above-described paper feeding / conveying operation is repeated, and upon completion of the exposure processing of the final document (D5) and discharging, all the document bundles are stacked on the discharge tray unit 360.

As described above, according to the present embodiment, the leading edge of the next original D as well as the original D to be read is platen glass 11
Since a plurality of originals are arranged in a row in the conveyance path by making them stand by at a position sandwiched between 1 and the conveyor belt 341, the interval between the read original and the next original is sufficiently short, and the original that has been read is discharged. It is possible to reduce the time for transporting the next document to the reading position. Further, when stopping the original at the reading position, the moving amount of the original is detected and controlled based on the number of pulses generated by the rotary encoder RE without using the original stopper, so that the positioning accuracy at the reading position is stable. Of course, it is possible to omit the mechanism for taking the document stopper in and out of the platen glass.

Further, as described above, in order to shorten the time required for document replacement, a plurality of documents are arranged in a line between the reading unit and the separating / feeding means, and the registration sensor PS6 serving as a reference for controlling the reading position is used. Even if two originals are arranged between the reading unit and the reading unit, the two pulse counters PC1 and PC2 are processed in parallel for each original as described above.
The amount of movement can be managed for each document.

(B) ADF Mode (Large-Size Single-Sided Original) FIG. 15 is a timing chart showing the operation of conveying a large-sized single-sided original, and FIG. 16 is a schematic diagram showing the process of conveying a plurality of originals.

(B1) When a large size document (B4 size, A3 size, 11 × 17 inch size, etc.) is placed on the document placing section 310, the set detection sensor S1 is turned on and the ADF mode is set, and at the same time, the size is changed. When the detection sensor S2 is turned on and it is determined that the size is large, the mode is switched to the large size mode.

(B2) As shown in FIG. 16 (A), document D1
The process from the sending to the resist is the same as the small size mode described above.

(B3) The original document D1 is restarted, advances to a predetermined stop position of the platen glass 111, and stops (FIG. 16).
(See (B)).

(B4) The preliminary feeding of the next original D2 is carried out during the exposure processing of the original D1 (see FIG. 16C).

(B5) The original document D1 is discharged to the discharge tray unit 360 outside the machine through the reverse discharging unit 350, and the next original document D2 is generated.
Is conveyed to a predetermined position on the platen glass 111 and stopped (see FIG. 16D).

(B6) During the exposure process of the document D2, the subsequent document D3 is preliminarily fed out (see FIG. 16E).
In this embodiment, the pre-feeding and the registration rollers are set, but the exposure time may be further used to send the paper to the front side of the second intermediate conveyance roller 333 and stand by. or,
It is also possible to directly cause the roller 333 to wait for registration.

(C) R-ADF mode (double-sided original) (C1) Feed belt 311 of movable plate 310 and movable pressing plate
When the document stack D is placed on 317, the automatic document feeder 300 is activated, the ADF mode is set, the document set detection sensor S1 is turned on, and at the same time the document size sensor S2 is turned on to detect the document size. To be done. Further, the user operates the double-sided original designation button on the control panel of the copier body 100 to set and enter the double-sided copy mode.

(C2) FIG. 17 is a timing chart showing the operation in the R-ADF mode, and FIG. 18 is a double-sided original D1.
6A to 6D are schematic diagrams illustrating document transport paths D3 to D3. In these figures, the first surface of the first original D1 and the second original D2
Both the first surface of the third document D3 and the first surface of the third document D3 face upward and are placed on the document placing portion 310.

(C3) Next, by turning on the copy button on the control panel, the pressing motor M1 is started, the movable pressing plate 317 is raised, and the original stacks D1 to D3.
The uppermost surface of the sheet is pressed against the feed roller 321, the drive motor (main motor) M2 is turned on almost at the same time, the clutch CL1 is turned on at the same time, and the document feeding is started.

That is, the original D1 on the upper layer is rotated by the feed belt 324 which starts to rotate by the driving force of the driving motor M2.
Document D, which is the largest of the plurality of document bundles that have been sent out and separated and sent out by the reverse roller 325.
Only one sheet is separated and sent.

One sheet of the document D1 separated and fed as described above.
When the document straightening sensor S5 detects the leading edge of the document, the timer T1 starts counting, and when the timer T1 counts up, the drive motor M2 is turned off. At this time,
The value of the timer T1 is set so that the leading edge of the document abuts against the first intermediate conveyance roller pair 331 which is stopped due to the turning off of the registration clutch CL2, and the document is stopped and straightened. If the feeding speed up to this point is set to a low conveyance speed (for example, about 1/2 of the speed at the time of document replacement), the curl correction operation becomes more stable.

When the timer T2, which has detected the leading edge of the document by the bending correction sensor S5 and started the coefficient, counts up,
The drive motor M2, the clutches CL1, CL2 and CL3 are turned on, and the document is conveyed again. In accordance with this, the transfer speed is switched to high speed transfer. When the leading edge of the document crosses the passage detection sensor S6, the delivery clutch CL1 driving the drive roller 323 is turned off, and the feed belt 32
In No. 4, the document D1 is driven to rotate until the rear end of the document D1 passes through the sensor S3, and then stops.

When the document passage detection sensor PS6 is turned on, the pressing motor M1 is switched to the reverse rotation, and the driving plate 319 and the movable pressing plate 317 are lowered to release the pressing.

When the drive plate 319 has returned to the initial position,
When the pressing home position sensor S3 detects, the pressing motor M1 is stopped. Alternatively, when a plurality of originals are to be continuously shipped, the drive plate 319 and the movable pressing plate 317 are not returned to the home position, and the pressing detection sensor S4 is used.
Based on the detection signal of 1) or the drive start signal of the driving means in the separating direction, the descent drive of the drive plate 319 and the movable pressing plate 317 is stopped in the middle.

When the trailing edge of the first document D1 passes and the passage detection sensor S6 is turned off, the driving of the driving means is started based on this detection signal, and the driving plate 319 and the movable pressing plate 317 are raised. Then, the subsequent manuscript (the next manuscript D
2) Start pressing.

The first original document D1 sent out by the paper feeding means and conveyed by the first intermediate conveying roller pair 331.
Of the document is detected by the notification detection sensor S3 as to the passage of the leading edge of the document, is fed by the second intermediate conveyance roller pair 333 downstream between the guide plates, and is further fed between the guide plates 332 downstream thereof. Will be sent. Registration sensor (original passage synchronization sensor) located in a part of this feeding path
When the leading edge of the document passes through S7, the registration sensor S7 issues a detection signal to control document transportation. That is, the registration sensor S7 includes a drive motor M2 and a registration clutch C.
The operation of L2 or the like is controlled by the clock timer or the count of the encoder RE directly connected to the conveyor belt shaft.

Next, the document D1 is sandwiched between the conveyor belt 341 and the platen glass 111 (reading section) which rotate in the conveyor unit 340, and conveyed while being pressed against the platen glass 111. Then, the document is stopped by the count of the clock timer or the encoder RE directly connected to the conveyor belt shaft.

In this embodiment, an encoder sensor S16 for detecting the output of the rotary encoder RE directly connected to the conveyor belt 341 is provided, and when the registration sensor S7 detects the leading edge of the original, the encoder sensor S16 starts counting and a predetermined count is reached. Then, the drive motor M2 is turned off,
Further apply the motor brake. Conveyor belt 341 or second
The intermediate conveyance roller 333 rotates while being decelerated by the braking force, the inertial force, and the load. At this time, the encoder count continues to be counted, and when the predetermined count is reached, the clutch CL3 is turned off and the brake BRK1 is turned on at the same time. It has been forcibly stopped. Of course, the document may be stopped by a mechanical means such as a document stopper.

The first surface of the document D1 is platen glass 111.
At the upper stop position, exposure is performed by the exposure lamp of the scanning exposure unit 110, and a two-dimensional original image is formed on the photosensitive drum of the image forming unit 120 via a lens, a mirror, and the like.

The same exposure is repeated for the set number of copies, and a series of copying processes for the first side of the document D1 is performed.

During the exposure operation of the first surface of the original document D1, when the next original document D2 is sent out by the sheet feeding means and the front end of the original document is detected by the straightening sensor S5, the timer T1 starts counting and the timer is started. When T1 counts up, the drive motor M2 is turned off. At this time, the value of the timer T1 is set so that the leading edge of the document abuts against the first intermediate conveying roller pair 331 that is stopped by the turning off of the registration clutch CL2, and the document is straightened. The paper feeding speed up to this point is a low-speed transportation speed (for example, about 1/2 of the speed at the time of document replacement).
When set to, the straightening operation is stable.

(C4) When the timer T2, which started counting when the leading edge of the document is detected by the straightening sensor S5, counts up, the drive motor M2 and the clutches CL1 and CL2 are turned on, and the document is conveyed again. In accordance with this, the transport speed is switched to high-speed transport. When the leading edge of the document crosses the passage detection sensor S6, the timer T4 starts counting. Then, the sheet is nipped by the pair of first intermediate conveying rollers 331 and stopped at a first standby position between the paper feeding means and the reversing means, which does not prevent the reversal of the preceding document D1 outside the document conveyance path of the reversing means. The T4 is set so that At the first standby position, the reading of the first side of the preceding document is completed, and the waiting of the reverse of the preceding document is performed.

(C5) When the copying of the first side of the original document D1 is completed, the drive motor M2 is switched to the reverse rotation drive, the conveying belt 341 is rotated in the reverse direction, and the platen glass 1
The document D1 on 11 is nipped by the reversing conveyance roller pair 335 that rotates forward, makes a U-turn through the guide plate 336, and advances in the direction of the second intermediate conveyance roller pair 333 that rotates forward.

When it is detected in S17 that the leading edge of the document D1 has passed, the drive motor M1 is detected after a predetermined time by this detection signal.
Is switched to the normal rotation drive, the drive roller 342 rotates in the normal direction to rotate the transport belt 341 and the intermediate roller 333 in the normal direction, and the document D1 whose front and back are reversed is slid rightward in the drawing on the platen glass 111. Let Here, when the trailing edge of the original document D1 is detected in S17, the timer T8 starts, and after the timer counts up, the registration clutch CL2 is turned on to convey the next original document D2 that has been waiting in the first standby position. To start.

(C6) While the second surface of the preceding document D1 is being conveyed to the exposure position (reading position), the next document D2
The original document D1 and the next original document D2 are simultaneously transported by the transport belt 341 in the transport direction, while being sandwiched between the rotatable transport belt 341 and the platen glass 111. Then, at the same time that the preceding document D1 stops at the exposure position (reading position), the next document D2 is at the upstream position on the transport belt 341 at a predetermined distance, and at least the leading end of the next document in the transport direction is on the transport belt 341. It stands by at the second standby position.

At this time, the encoder count is started when the leading edge of the preceding document D1 which is in the process of reversing crosses the registration sensor S7, but the leading edge of the next document D2 also immediately crosses the registration sensor S7. And the preceding original document D1 which has been independently counted and counted
On the other hand, when the count up is started, the stop operation is started, and the count of the next original D2 is held.

(C7) When the exposure of the first document D1 is completed, the switching solenoid SL1 is turned on, and the CFF switching claw 353 is formed.
To the upper side and the passage to the lower side,
Rotates in the forward direction and sends the document D1 to the paper discharge reversing unit 350. That is, by the reverse rotation of the paper discharge motor M3 that is driven at the same time, the document D1 passes through the lower side of the paper discharge roller 351, the reverse paper discharge roller 354, and the lower path of the movable tray 363 which is a paper discharge tray.
Sent to 364.

At the same time, the next original D2 is also slidably conveyed on the platen glass 111 from the second standby position held by the conveyor belt 341 and the third intermediate conveyor roller pair 334, and the held count is restarted. When the predetermined count is reached, the drive motor is turned off. The conveyor belt 341 and the second intermediate conveyor roller pair 333 rotate while being decelerated by the inertial force and the load. At this time, the encoder count is further counted, and when the predetermined count is reached, the conveyor clutch CL3 is turned off and the brake BRK1 is simultaneously released. Is turned on to forcibly stop, and the scanner is positioned at the reading position.

(C8) The preceding document D1 is conveyed by the paper output reversing unit 350 even during scanning exposure by the exposure lamp on the first surface of the document D2 stopped at the exposure position (reading position) on the platen glass 111. Being transported on the road.

During the scanning exposure of the original D2, the preceding original D
1 is conveyed through the discharge reversal unit 350 (discharge unit), and when the reverse end sensor S11 detects the trailing edge of the document, the discharge motor M3 is switched to the normal rotation after a predetermined time, and the document D7.
Is conveyed in the opposite direction, is conveyed below the switching claw 357, and is ejected to the movable tray 363 (paper ejection stack portion) with the first surface thereof facing downward.

Here, since a new original is not fed to the paper output reversing section 350 until the reading of the first and second sides of the original D2 is completed, at least the next original D
It is possible to reverse the discharge by fully using the time until the reading operation of the second side of No. 2 is completed. Therefore, in the paper discharge reversing unit 350, when the document is detected by the reverse paper discharge sensor S11 at the trailing edge and the paper discharge motor M3 is rotated in the normal direction after a predetermined time, the document is conveyed at a speed slower than the document replacement speed and the movable tray 363. The paper is ejected on top.

As a result, it is possible to discharge the sheet at a low speed during the sheet discharging and transport, and it is possible to reduce the protrusion of the sheet onto the movable tray 363 during the sheet discharging to improve the original alignment and to smoothly perform the reverse sheet transporting operation. You can Further, in S11, it is also possible to switch to the low speed at the same time as the rear end detection and perform the above operation.

(C9) The original D2 having undergone the exposure processing of the first surface is fed back on the platen glass 111 by the reverse rotation of the transport belt 341, and the reverse transport roller pair 3 of the reversing means.
The sheet 35 is nipped and conveyed by the 35 and the second intermediate conveyance roller pair 333.

Document D that has passed through the conveyance path in the reversing means
2 is fed to the right end of the platen glass 111 in the figure again in the state of being turned upside down, and is nipped and conveyed by the conveyor belt 341 to slide on the platen glass 111, and similarly, the brake is stopped after counting. The same scanning exposure as that described above is performed on the second surface of the document D2 in the stopped state.

The document D2 which has been subjected to the double-sided exposure processing is conveyed by the conveyance belt 341 and sent to the paper discharge reversing unit 350, where the document D2 is conveyed with its front and back reversed.

The original D2 which has been conveyed through the paper output reversing section 350 and which has been turned upside down is discharged onto the movable tray 363 outside the apparatus and mounted on the preceding original D1.

As described above, when the double-sided document copy mode is selected, the automatic document feeder of the present embodiment feeds out one double-sided document on the document placing section 310 and reads it by the scanning exposure optical system reading section. Before the reading operation of the first side of the document D1 is completed by
Let it be fed to the standby position. Then, when the reading operation of the first surface of the original document D1 is completed and the second surface of the original document D1 is conveyed to the reading position by reversing the original surface by the reversing means, the preceding original document D1 and the first original document D1 are conveyed by the conveying means. The next original D2, which has been waiting at the first waiting position, is moved back and forth in the carrying direction to be carried at the same time.

As a result, the second surface of the preceding original document D1 is made to reach the reading position and at the same time, the next original document D2 is set to the first position.
The next original document D2 is conveyed from the standby position to the second standby position upstream of the preceding original document D1 by a predetermined interval, and after the second surface reading of the preceding original document is completed, the preceding original document D1 is discharged and the next original document D2 is made to stand by at the second standby position. It is characterized in that the first surface of the sheet is conveyed to the reading position at the same time, and the above operation is repeated thereafter until there is no more original.

According to such a conveying process, when the second surface of the preceding original document D1 is read, the next original document D2 can also be made to stand by at the upstream vicinity where it is also sandwiched by the conveying belt 341. After the two-sided reading is completed, the first side of the next original D2 can be conveyed to the reading position in a short time, whereby the original conveying time can be shortened and the copy productivity is remarkably improved.

That is, since the reversed original document and the next original document are conveyed at the same time, the next original document D2 together with the preceding original document D1 can be put on standby within the conveyance range of the conveyance belt 341, and the conveyance distance of the conveyance belt 341 is restricted. Then, the next original D2 can be brought close to the preceding original D1 as much as possible and can be put on standby.

Further, before carrying out simultaneous conveyance of the reversed original document and the next original document, the next original document D2 is separated from the document placing table in advance and made to stand by at the first standby position.
When there is enough time for standby operation to the standby position, low-speed separation operation and document posture correction operation can be performed, and separation from the document table and conveyance to the second standby position can be performed continuously. In comparison, the separation performance can be improved, the problem of documents can be stabilized, and a reliable document replacement operation can be performed.

(D) RDH mode (single-sided document circulation / transport mode) FIG. 19 is a timing chart in the RDH mode and the R-RDH mode described later. FIG. 20 is a schematic diagram showing the document circulating / transporting path in this mode.

When the first side of the original is exposed by the platen glass 111, the original D follows the paper feed path to the platen glass 111 through the paths a, b, c, d and e, and after the exposure processing, the switching claw is used. It passes through the upper surface of 353 and enters the holding piece portion 311B of the feeding belt 311 via the paths f, g, and n.

(D1) Initialization (1A) The main switch of the copying machine main body 100 is turned on. When the main switch is turned on, the pressing motor M1 starts to rotate in the reverse direction and the offset correction motor M4 starts to rotate in the normal direction. At the same time, the paper discharge motor M3 and the bottom return clutch CL4 are turned on to start the driving rotation of the driving roller 312A.

(1B) Movable pressure plate home position stop When the main switch is turned on, the pressure motor (stepping motor) M1 is driven to rotate in the reverse direction to swing the drive plate 319, and the actuator portion 319A fixed to the swing shaft 317A. When the pressing home position sensor S3 is turned on, the reverse rotation of the pressing motor M1 is stopped by the detection signal,
The drive plate 319 and the movable pressing plate 317 are stopped at the lowest initial position (home position). This is effective in absorbing the time lag of the drive gear and the sensor on. At this home position stop position, a clearance capable of accommodating a predetermined maximum amount of the document bundle D is maintained.

(1C) Document Bundle Placement When the document bundle D is placed on the feeding belt 311 and the movable pressing plate 317, the set detection sensor S1 is turned on and the ADF mode is set. At the same time, the size detection sensor S2 is turned on to detect the document size. Next, RDH mode or RR
Select and input the DH mode.

(1D) Home Position Search Operation of the Offset Correcting Roller The offset correcting roller 355 is movable in the direction orthogonal to the sheet conveyance and is driven by the offset correcting motor M4 which is driven and rotated by turning on the main switch. . An offset home position sensor S15 for detecting the roller position is provided outside the sheet passage of the offset correction roller 355.

When the main switch is turned on, if the sensor S
If 15 is off, rotate the offset correction motor M4,
When the sensor S15 is turned on by moving the roller 355 in the depth direction, the motor M4 is stopped. The motor M4 is a step motor, and after stopping, a constant voltage is applied to bring it into a hold state. If the sensor S15 is on, the motor M4
Reversely, the roller 355 is moved in the front direction to turn off the sensor S15 once, and then the motor M4 is again rotated forward to stop and hold the motor M4 when the sensor S15 is turned on. By this operation, the motor M4 to the roller 355
The roller 355 always stops at an accurate predetermined position regardless of rattling of gears and the like. This predetermined position is usually adjusted to be substantially at the center of the possible range of the roller 355.

(1E) Bottom-Returning Feeding Belt Home Position Search Operation The bottom-returning feeding belt 311 having a nipping piece portion 311B partially hung between the driving roller 312 and the driven roller 313 has the bottom-returning feeding belt 311 shown in FIGS. Through hole for home position detection as shown in
311C is open. When the main switch is turned on, the paper discharge motor M3 and the bottom return CL4 are turned on, and the drive roller 31
Rotate 2 The drive roller 312 is a one-way rotating clutch C.
It is driven via L6 and always rotates in the direction of the solid line arrow regardless of the forward / reverse rotation of the motor M4.

When the home position detecting hole 311C on the feeding belt 311 passes through the belt home position sensor S13, the sensor S13 is turned off, and after a predetermined time, the bottom return clutch CL4 is turned off and, at the same time, the paper discharge brake BRK2 is turned on. Then, the drive roller 312A is suddenly stopped. As shown in the figure, the bottom return feeding belt 311 has the sandwiching piece portion 311B on the extension of the offset correction roller pair 355, and the cutout portion 311D is aligned with the position of the separating lever 315A.

(2) Circulation of Original Document The above-described initialization operation completes the preparation for feeding the original document, and then the feeding of the original document is started. FIG. 20 is a schematic diagram showing a single-sided document conveyance process.

(2A) When the copy button is turned on, the pressing motor M1, the paper discharge motor M3, the bottom return clutch CL4
Is turned on, and ADF and copy can be started.

(2B) When the copy button is turned on, the bottom return clutch CL4 is turned on to start the low-speed drive rotation of the paper discharge motor M3. As a result, the driving roller 312A is rotated and the feeding belt 311 is rotated. When the detection hole 311C of the feeding belt 311 passes through the belt home position sensor S13, the detection signal causes a feeding belt after a predetermined time.
311 is stopped by a brake and the notch main part and the sandwiching part are set to the basic position, and then the number-of-parts separating solenoid SL3 is turned on, and the separating lever 315A passes through the notch 311D.
Comes into contact with the lowermost layer of the document stack.

(2C) When the copy button is turned on at the same time,
The pressing motor (stepping motor) M1 is driven and rotated,
The movable pressing plate 317 swings and rotates through the drive plate 319 fixed to the swing shaft 317A and the torsion spring 317B, and the leading end of the movable pressing plate 317 rises to lift the stacked document stack D. In the ascending process, the swing angle of the swing shaft 317A counts the pulse count C1 by a rotary encoder or the like.

(2D) When the upper surface of the document stack D stacked on the movable pressing plate 317 is lightly pressed against the outer peripheral surface of the feed roller 321 which is lowered to a predetermined position by its own weight, the movable pressing plate 317 is moved. Feeding roller 321 with the stack of originals sandwiched
Raise. After rising by a predetermined amount, the pressure detection sensor S at the tip
4 is turned on, and counting is started. When it further oscillates, the frame body 321 holding the feed roller 321 comes into contact with a fixing member (not shown) and stops. However, drive plate 319
Is further driven and rotated to rotate counterclockwise while compressing the torsion spring 317B, so that the movable pressing plate 317 and the driving plate 319 are rotated.
The intervals between are getting narrower. When the pressure detection sensor S4 is turned on, the initial set pressure (for example, the roller own weight of 50 g) is reached, and counting of the count C1 is stopped.

(2E) The paper bundle thickness of the document bundle D is detected by the output of the count C1, and the press is predetermined by the document size detected by the size sensor S2 or the setting input of thick paper or thin paper. The designated pulse is determined by the pulse table.

The original sheet bundle thickness is detected by the count value of the count C1 and the sheet bundle thickness is set to be divided into, for example, three stages of high, medium and low.

Further, as the document paper size, for example, B5 to
A3 size is set, and this is detected by the size detection sensor S2. When a stack of document sheets of a plurality of document sizes is mixedly mounted, the user specifies it by pressing a mixed mounting key mounted on the operation panel of the copying machine main body.
The paper thickness of one original paper is designated by pressing a thin paper key or a thick paper key placed on the operation panel.

As described above, the original sheet bundle thickness and the original size are automatically detected by the respective sensors, and the mixed originals and the sheet thickness are manually set.

The pressure pulse table is set in advance by these detected values and manual setting, and is stored in the nonvolatile memory, and the count C2 is determined by these sheet condition inputting means.

(2F) When the count C2 is input by the above designated pulse and the drive plate 319 is further driven to continue counting the count C2, and the drive plate 319 is swung until the designated count number C2 counts up, The winding amount of the torsion spring 317B increases, the elastic force changes almost linearly, and the pressing force increases.

(2G) When the count C2 is counted up, the movable pressing plate 317 presses the document D against the feeding roller 321 with a predetermined pressing force (for example, 100 g), and the pressing motor M1 stops driving.

(2H) At the same time as the driving of the pressing motor M1 is stopped by the above count-up, the delivery clutch CL1
The drive motor M2 is turned on, the drive motor M2 is rotated at a low speed, and the document feeding is started. That is, the feed belt started to rotate by the driving force of the drive motor M2 rotated at a low speed.
The original document in the upper layer is sent out by 324, and only the uppermost original document D1 among the plurality of original documents sent out by the reverse roller 325 is separated and sent.

(2I) The front end of one original document D1 separated and fed as described above is detected by the straightening sensor S5, and a predetermined time (timer T
1) After the lapse of time, the drive motor M2 is turned off, the registration clutch CL2 is turned off, and the first intermediate conveying roller (registration roller) 331 is struck to form an accumulation, and the feeding bend of the document D1 is corrected ( See FIG. 20 (A).

(2K) Further, after a lapse of a predetermined time from the detection of the leading edge of the original by the straightening S5 by the timer T4,
The drive motor M2 is rotated again. At this time, the drive motor M2 is rotated at a high speed, the registration clutch CL2 and the transport clutch CL3 are turned on simultaneously with the delivery clutch CL1, and the document D1 is transported downstream. When the leading edge of the document D1 crosses the passage detection sensor S6, the feed clutch CL1 driving the drive roller 323 is turned off, and the feed belt 324 is driven to rotate until the trailing edge of the document D1 passes through the sensor S6. After that, the drive motor M
Then, the document D1 is conveyed by the first intermediate conveyance roller pair 331.

(2L) Further, upon completion of counting by the timer T4, the pressing motor M1 is switched to the reverse rotation, the driving plate 319 and the movable pressing plate 317 are lowered, the pressing is released, and the driving plate 319 is moved to the initial position. When the home position detection sensor S3 detects that the pressure motor M1 has been returned to, the pressing motor M1 is stopped. Alternatively, when a plurality of originals are continuously fed, the driving plate 319 and the movable pressing plate 317 are not returned to the home position position, but based on the detection signal of the pressing detection sensor S4 or the driving start signal of the driving means in the separating direction. The descent drive of the drive plate 319 and the movable pressing plate 317 is stopped in the middle.

(2M) After the sensor S13 detects the passage of the home position detecting hole 311C on the feeding belt 311, and after a predetermined time is counted by the timer T3, the member separating solenoid SL3 of the pushing-up means 314 is turned off and the pushing-up lever is pushed. 314A
Is descended. As a result, the separating lever 315A held on the push-up lever 314A also follows and descends by its own weight to release the push-up of one end of the document stack, making a diameter contact with the bottom of the document on the lowermost layer, and S14 Turns on.

Here, if the original stack is first placed on the original placing section 31.
When the separator lever 315A is placed below the separator lever 315A of 0 or the separator lever 315A enters between the document stacks, the copy separator sensor S14 does not detect the stop position, and the signal causes the separator lever 315A located above to be turned off by turning off the solenoid SL3. While lowering the push-up lever 314A, the solenoid S
When L4 is turned on, the separating lever 315A inclines and slides back, and subsequently, when the solenoid SL4 is turned off, the spring 315A is turned off.
The separator lever 315A is moved forward by being biased by E and is inserted below the cutout 311D of the feeding belt 311 below the document stack.

(2N) Next, when the leading edge of the document D1 passes the registration sensor S7 and the signal is turned on, the conveyor belt 34
The counting is started by the encoder sensor S16 for the encoder plate RE, which is directly connected to the first driving roller 342 and the second intermediate conveyance roller pair (registration roller) 333. After the predetermined count (φ1) by the encoder RE, the drive motor M2 is turned off. Further, at this time, the encoder plate RE starts counting, and after a predetermined count (φ2), the registration clutch C
L2 and the transport clutch CL3 are turned off, and the transport brake BR
K1 is turned on, and the rotation of the transport belt 341 and the second intermediate transport roller pair 333 is stopped. At this time, the leading edge of the document D1 reaches a predetermined standby position (a position at a distance L1 from the stop position, for example, 236 mm) of the platen glass 111 and stops (see FIG. 20B).

When the leading edge of the first original D1 passes the registration sensor S7 and the detection signal is turned on, the pressing motor M1 starts the pressing operation of the drive means based on the detection signal, and the drive plate 319 and The movable pressing plate 317 is raised to continue pressing the subsequent document D2.

(2O) After a predetermined time from the count-up (φ2) of the encoder plate RE, the drive motor M2 and the delivery clutch CL1 are turned on, and the delivery roller 321
Then, the feed belt 324 rotates at a low speed to feed the original D2 at a low speed, hit the first intermediate conveyance roller pair (registration roller) 331 to form an accumulation and stop the same as the above-mentioned original D1 ( See FIG. 20 (C).

(2P) Next, after a predetermined time, the drive motor M
2, the delivery CL1, the registration clutch CL2, the conveyance clutch CL4 are turned on, the conveyance brake BRK1 is turned off, the originals D1 and D2 are conveyed at high speed, and the driving motor is driven when the original D1 reaches a predetermined exposure position on the platen glass 111. The original D1 is stopped at the exposure position by turning off M2, the transport clutch CL3 registration clutch CL2 off, and the transport brake BRK1 on, and at the same time, the original D2 is stopped at a predetermined standby position on the platen glass 111 (FIG. 20).
(D)). That is, in the present embodiment, the moving amount of the document D is managed by counting the number of pulses of the rotary encoder RE with the registration sensor S7 as a reference without using the document stopper, and the document D is conveyed to the reading position. is there.

(2Q) With both originals D1 and D2 stopped,
The document D1 is scanned and exposed by a signal from the copying machine body (see FIG. 20E). That is, the document D1 is exposed by the exposure lamp of the scanning exposure unit 110 in a stopped state on the platen glass 111, and a document image is formed on the photosensitive drum via a lens, a mirror and the like. And the original D1
A series of copy processes for is performed.

During the exposure operation, the drive motor M2 and the clutch CL1 are actuated by the count-up of the timer, the rotation of the feed belt 324 is started, the next original D3 is sent out, and the registration operation is controlled by the timer. Then, the document D3 is stopped at a position where the leading edge of the document D3 maintains a predetermined distance L1 from the leading edge of the document D2.

Therefore, at this time, the three originals D1 to D3 are arranged in a row in the transport path from the separating / feeding means to the reading section with a predetermined space L1 between them.
At this time, the original document D1 is placed at the reading position of the platen glass 21, and the original document D2 is placed at a position that is stretched between the conveyor belt 141 and the second intermediate conveyor roller pair 132 (second conveyor roller pair). The document D3 waits at the position where it hits the registration roller 331, and the documents D2 and D3 stand by in a state where the subsequent conveyance can be performed stably.

(2R) Original Replacement (Refer to FIG. 20F) After the exposure operation of the original D1 is completed, the driving belt M1 is rotated at a high speed to rotate the conveyor belt 141 and further rotate the paper discharge motor M3 at a high speed. The exposed original document D1 passes through the paper discharge reversing unit 350 and is returned to the original document placing unit 310. Due to the high speed rotation of the discharge motor M3, the document D1 passes below 351 and is already switched by the RDH switching solenoid SL2.
Oscillates to move in the guide plate 356B through the branch portion which switches and opens the upper passage. When the leading edge of the document D1 is detected by the paper discharge sensor S9 during this conveyance, the timer starts counting. When the timer counts up, the bottom return clutch CL4 is turned on. At this time, if the deviation detection sensor S10 is off, the deviation correction motor M4 is started to rotate in the depth direction. If the sensor S10 is turned on, the sensor is moved to the front side, turned off, and then turned inward again to stop at the same time as the sensor is turned on.
Align it by abutting against and correcting the deviation. The timer is set to turn on the bottom return clutch CL4 so that the front end of the document D1 is pinched by the pinching piece portion 311B of the feeding belt 311.

In the present embodiment, the conveyance distance from the paper discharge roller 351 to the sandwiching piece portion 311B has an interval equal to or larger than the paper passing size, but the rear end of the document D1 is discharged by a timer independent of the timer. After passing through the paper roller 351, the deviation correction motor M4 may be turned on so that the distance from the sandwiching piece 311B to the paper discharge roller 351 is maintained shorter than the original size.

(2S) Further, the bottom return feeding belt 311
Then, the offset correction roller pair 355 is rotated, and the document D1 is inserted below the upper document stack. Here, the separating lever 315A of the copy number separating means 315 is raised upward by a certain amount by the copy number separating solenoid SL4, and the sandwiching piece portion is provided.
The document D1 whose front end is nipped at 311B is inserted below the final undocumented document.

(2T) The original document D4 is further sent out after the completion of the original document replacement operation, and the movable pressing plate 317 is lowered immediately after the registration is completed. It passes over the plate 317 and strikes against the document leading edge stopper 318 and stops.

(2U) When the document D4 is sent to the registration position, the rear end of the document D4 passes through the separating lever 315A,
The separating lever 315A moves upward, the copy number separating sensor S14 is turned on, and it is detected that the last document of the first circulation is sent out.

(2V) After the document D4 is conveyed to the second stop position, the document D1 returned to the document placing section 310 is fed again while the document D3 is being exposed. Similarly, when D2, D3, and D4 are sent out and D4 returns, the copy number separating solenoid S
The L3 is operated to move the separating lever 315 to the lower side of the document D4.
Insert A. This operation is repeated a predetermined number of times.

In this embodiment, after the registration feeding is completed, the movable pressing plate 317 is configured to return when it is lowered, but the feeding operation may be performed after the completion of the returning. here,
A paper pressing lever 319 provided on the upstream side of the separating lever 315A in the conveying direction serves to surely insert the returning original document under the original document stack, and lightly presses the original document by its own weight.
The paper pressing lever 310Z is also effective for stabilizing the operation of the separating lever 315A when conveying curled paper or a small number of originals.

(3) R-RDH Mode (Double-sided Original Circulation and Transport Mode) The above operation is for single-sided copying of a single-sided original in the RDH mode. In the R-RDH mode in which a double-sided original is copied on both sides, the original is reversed in the first cycle as in the single-sided operation.
Only odd-numbered pages are copied (see FIG. 9C), and even-numbered pages are copied in the second cycle (see FIG. 9D). Of course, the paper feeding operation of the copying paper on the copying machine main body 100 side is also performed in accordance with the RDH mode and the R-RDH mode.

21 and 22 are for copying both sides of a two-sided original R
FIG. 6 is a schematic diagram showing a document conveyance process in a −RDH mode. The document conveyance for even-page copying of a small size document will be described below.

(3a) FIG. 21 (a) shows a state in which the first original D1 on the even-numbered page in the second cycle is conveyed intermediately. When the preceding final document D4 of the first cycle is stopped at a predetermined position on the platen glass 111, the first document D1 of the second cycle is fed to the platen glass 111.
And the leading edge of the document D1 is stopped at a standby position where a predetermined distance L1 is maintained from the leading edge of the preceding document D4.

(3b) Next, the original D4 is a platen glass
Exposure processing is performed at a predetermined position on 111. During this D4 exposure operation, the next original D2 is sent out and the registration roller 331
And wait for registration (see FIG. 21 (b)).

(3c) The originals D4 and D1 are simultaneously conveyed by the forward rotation of the conveyor belt 341, and a predetermined time after the trailing edge of the original D1 has passed the registration sensor S7, the conveyor belt 341 is driven in reverse to drive D1. Send to inversion path 336. The final original D4 in the first cycle is strongly nipped by the discharge roller 351.
The conveyor belt 34 is rotated in the reverse direction by the driving force of the discharge motor M3.
It is conveyed in the direction of the paper discharge paths f, g, and h against 1 (Fig. 2
1 (c)).

(3d) Subsequently, the document D1 is fed back, is reversed through the path i, and reenters the platen glass 111 with the second surface facing downward. The document D4 advances toward the document placing number 310. The reversal detection sensor S17 turns off M2 after a lapse of a predetermined time to detect the leading edge of the document D1 and switches to the normal rotation, but the reversing roller always rotates in the normal direction, so that the document D1 is continuously fed onto the platen glass 111. At this time, the sensor S7
After a lapse of a predetermined time from the detection of the leading edge passage of the document D1 by, the delivery clutch CL1 is turned on and the document D2 is delivered at a predetermined distance from D1 (see FIGS. 21D and 21E).

(3e) The originals D1 and D2 are simultaneously conveyed,
The document D1 is stopped at a predetermined position on the right end of the platen glass 111 and is subjected to an exposure process. At this time, the document D2 advances to a predetermined standby position on the platen glass 111 and is stopped. D3 is sent during D1 exposure, and registration roller 331
Stop at the position where it hits (Fig. 21 (f), Fig. 22 (g)
reference).

(3f) The document D1 is conveyed to the discharge reversing section 350. At the same time, the document D2 enters the surface of the platen glass 111 (see FIG. 22 (h)).

(3g) The original D2 is turned upside down by the turning guide plate 336, and the platen glass is turned with the fourth side facing downward.
Enter one end of 111. During this time, the leading document D1 passes through the reversing paths j, k, m, and h in the paper ejection reversing unit 350 and advances to the document placing unit 310 with the first surface facing upward (FIG. 22).
(See (i)).

(3h) Detection of the leading edge of D2 by the registration sensor S7 After a predetermined time, D3 is pulled out and sent out to obtain the original D.
2 and D3 are simultaneously conveyed, and the original D2 is a platen glass 11
1 Stop at a predetermined position on the right end and receive exposure processing. At this time, the document D3 advances to a predetermined standby position on the left side of the platen glass 111 and stands by, and the leading end spacing of these documents D2 and D3 is maintained at L1. The document D4 is sent out during the exposure of the document D2 and stopped at the position where it hits the registration roller 331 (see FIG. 22 (j)).

In the same manner, the even-numbered page original is turned upside down by the intermediate feeding unit 330, and is fed onto the platen glass 111 with the even-numbered page face down, and is switched back by the discharged sheet inverting unit 350 after the exposure processing. The sheet is inverted and returned to the bottom layer of the original stack on the original placing section 310 with the odd page surface facing upward (see FIGS. 22 (k) and (l)).

The above is the operation of conveying a small-sized document,
When conveying a large-sized document (B4 size, A3 size, 11-inch width paper), etc., the standby position for the subsequent document is provided on the upstream side of the platen glass 111 at the branch portion between the document forward conveyance path c and the reverse conveyance path i. It may be set near the registration roller 334.

The feeding belt having the sandwiching piece and the movable pressing plate in the automatic document feeder of the present invention are effective when applied to a recycle automatic document feeder (RDH). The present invention can be widely applied to a sheet re-feeding device in which the sending sheet setting unit and the discharged sheet placing unit are the same.

[0205]

As described above, according to the automatic document feeder of the present invention, the documents set or re-stacked on the document placing table are fed from the uppermost sheet of the document placing table to the sheet feeding section and the processing section. After that, since it is returned to the lowermost layer of the original stack on the original placing table again in a closed loop, the originals are not contaminated due to front and back friction between the originals. Further, the automatic document feeder of the present invention does not require suction means or the like, is small in size and has a simple structure, and thus is not only effective in reducing the manufacturing cost, but also does not generate noise or vibration. Has excellent advantages.

Further, according to the automatic document feeder of the present invention, ADF, R-ADF, RHD, R-RHD, CFF.
Each mode is enabled, and it is possible to efficiently convey a plurality of originals that are continuously conveyed with a simple structure and control. As a result, it is extremely effective in shortening the copy time (improving copy productivity).

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a copying machine equipped with an automatic document feeder according to the present invention.

FIG. 2 is a sectional view of the automatic document feeder.

FIG. 3 is a perspective view of a main portion of a document placing portion.

FIG. 4 is a perspective view of a feeding belt and related members of the document placing portion.

FIG. 5 is a front sectional view of a document placing section and a feeding section.

FIG. 6 is a side view of a copy number dividing means and a pushing-up means.

FIG. 7 is a schematic diagram showing a conveyance state of a return document on a document placing section in a document circulation mode.

FIG. 8 is a schematic diagram showing a document conveyance path in ADF mode and R-ADF mode.

FIG. 9 is a schematic diagram showing a document transport path in an RDF mode and an R-RDH mode.

FIG. 10 is a schematic diagram showing a document transport path in CFF mode.

FIG. 11 is a block diagram of a drive system of the automatic document feeder.

FIG. 12 is a configuration diagram of the drive system.

FIG. 13 is a timing chart of the ADF mode small-size document conveyance operation.

FIG. 14 is a schematic diagram showing a document conveyance process in the above mode.

FIG. 15 is a timing chart showing an ADF mode large-size document conveying operation.

FIG. 16 is a schematic diagram showing a document conveyance process in the above mode.

FIG. 17 is a timing chart showing an original conveying operation in R-ADF mode.

FIG. 18 is a schematic diagram showing a document conveyance process in the above mode.

FIG. 19 is a timing chart showing a document feeding operation in the RDH mode and the R-RDH mode.

FIG. 20 is a schematic diagram showing a document conveyance process in RDH mode.

FIG. 21 is a schematic diagram showing a document conveyance process in R-RDH mode.

FIG. 22 is a schematic diagram showing a process of continuing document transportation in the above mode.

[Explanation of symbols]

 100 Copier main body 110 Scanning exposure section 111 Platen glass (reading section) 120 Image forming section 300 Recycling type automatic document feeder (RDH device) 310 Document placing section 310Z Paper pressing lever 311 Feed belt 311A Seam section 311B Nipple section (Gripper part) 311C Detection hole 311D Notch part 312A Drive roller 314 Separation lever pushing up means (pushing up means) 314A Pushing up lever 315 Separation means 315A Separation lever 316 Width stopper plate 317 Movable pressing plate 318 Original tip stopper 319 Drive Plate 320 Feeding Unit 321 Feeding Roller 324 Feed Belt 330 Intermediate Conveying Unit 331 Registration Roller (First Intermediate Conveying Roller Pair) 334 Registration Roller (Third Intermediate Conveying Roller Pair) 340 Conveying Unit 341 Conveying Belt 350 Paper Ejecting Reversing Unit 351 Ejecting Paper roller 355 Circulation paper ejection roller (deviation correction roller) 360 Paper ejection tray section a, b, c, d, e, i Paper feed path f, g, h, j k, m, n discharge path S7 registration sensor S17 inversion detection sensor D, D1 to D4 original (original bundle)

Claims (1)

[Claims] 1. A first transport path for separating one of a plurality of originals stacked on a document placing section and feeding the separated original to an image reading section, and the first reading path of the image reading section. A second conveyance path which is located near the original conveyance, reverses the original from the image reading unit and returns it to the image reading unit again, and conveys the original fed to the image reading unit and stops at a predetermined image reading position And a conveying unit that conveys and carries out the document after image reading, and a document that is located downstream from the image reading unit and conveyed from the conveying unit and is conveyed to the document placing unit on the reading unit with the same upper surface. And a third transport path for returning the document to the image reading unit, and a fourth document path for returning the document carried out from the transporting unit to the document reading unit with the side opposite to the upper surface on the reading unit facing up. Of the original document carried out from the image reading unit on the sheet ejection tray outside the machine. A fifth conveyance path for ejecting the original reading surface downward and a sixth conveyance path for reversing and ejecting the original conveyed from the image reading unit to a discharge tray outside the machine. An automatic document feeder which is characterized in that