JPH03249041A - Automatic document conveyor - Google Patents

Abstract

PURPOSE:To enhance stabilization of the performance of an automatic document conveyor in separating copies, smooth conveying of copies, prevent the ends of each document from being damaged and reduce the load of a motor by feeding documents at low speed. CONSTITUTION:A first document is conveyed by a conveying means from a document stand 11 to a predetermined position of an image exposing portion 101 and stopped there, and while the document is scanned and exposed for a predetermined number of documents, the next document is conveyed to a position before the document stand 11 and past the first document being scanned and exposed and also waiting operation is completed. Next, operation of discharging from the image exposing portion 101 the first document having been scanned is started and also the waiting second document is conveyed to the predetermined position of the image exposing portion 101. When the waiting position is set such that the distance by which a document is conveyed from the waiting position to the predetermined position of the image exposing portion 101 is smaller than that required for the document having been scanned and located in the predetermined position to be discharged, the first document being discharged is continuously discharged and discharge is completed before the document is scanned and exposed for at least one copy thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to improvements in automatic document conveyance devices in recording devices such as electrophotographic copying machines, image reading devices, and the like.

[Background of the invention]

An automatic document feeder is generally used by being mounted on a document table glass (platen glass) of an image exposure unit of a copying machine or the like.

In an optical system moving type copying machine equipped with this automatic document feeder, the automatic document feeder feeds sheets of originals (hereinafter simply referred to as originals) one by one from the document tray (stack section) on which they are placed. The document is fed onto a document table glass by a conveyor belt, exposed there by an exposure section lamp in the main body of the copying machine, and then further conveyed onto a document discharge table.

Conventionally, the operation of exchanging originals on the original platen glass by an automatic document feeder is to send out the next original from the stack section after a paper ejection sensor detects that the original on the original platen has been ejected. It was conveyed upward and stopped at a predetermined position. As a result, it takes a long time to exchange originals, and therefore a lot of time is required for copy processing, resulting in a decrease in copy productivity.

[Problem to be solved by the invention]

When using an automatic document feeder to automatically feed and eject documents onto the document table, copy productivity can be increased by 10% if the document is exchanged within the return time of the scanning optical system.
It becomes 0% and no time is wasted. However, as the size of the originals becomes smaller, the distance between the originals increases, resulting in a loss of conveyance time and lowering copy productivity.

To achieve this, it is necessary to increase the document transport speed from the document double-feed prevention position in the stack unit to the document stop position on the document table glass surface.

However, increasing the document conveyance speed causes various problems such as an increase in the size of the motor, an increase in power consumption, generation of noise, abrasion of the conveyor belt, an increase in the degree of document damage, and a decrease in document separation performance.

Japanese Unexamined Patent Application Publication No. 1-236136 discloses a conventional technique for a document conveying device that eliminates the above problem and shortens the time required to exchange documents without increasing the document conveyance speed.

This document conveying device stops conveying the first document at a predetermined position, then stops conveying the second document to a position adjacent to the predetermined position and not on the upstream platen, and then finishes the image reading process. The first document is conveyed by the conveying means to a downstream position on the platen that is adjacent to the predetermined position and is at a position where it can be conveyed, and at the same time, the second document is stopped at a predetermined position, and the third document is conveyed. This procedure is repeated for subsequent documents, and the conveyance is stopped one after another.

However, this document conveying method has the drawback that since three documents are conveyed at the same time, the motor load increases and a large amount of current is required. Furthermore, since three originals move simultaneously, if a jam occurs, the next original may collide with the preceding original and be damaged, leaving little room for jam detection and complicating jam handling.

[Means to solve the problem]

The object of the present invention is to solve the above-mentioned problems in an automatic document feeder and to increase the number of copies processed.

The automatic document feeder of the present invention that achieves the above object separates the originals one by one from a stack of originals stacked on a document placement table, feeds the originals one by one to an image exposure section, and stops the documents at the image exposure section. In an automatic document feeder that performs scanning exposure by moving an optical system and transporting the document to a document output tray after exposure,
A paper feeding means for feeding the original to the image exposure section, a transport means for stopping the transport of the original to a predetermined position of the image exposure section, a paper ejection means for transporting the original after exposure, and these means. and control means for driving control, and the paper feeding means, the conveyance means, the paper ejection means, and the control means cause the conveyance means to stop conveying the first document from the document placement table to a predetermined position of the image exposure section. , while performing scanning exposure for a predetermined number of copies, the next original is transported to a position downstream from the original placing table and upstream from the original being scanned and exposed, and the standby operation is completed, and then the first original that has been scanned is transported. The operation of discharging the document from the image exposure section is started, and the second document that has been waiting is stopped being transported to a predetermined position in the image exposure section, and the amount of transport from the standby position to the predetermined position in the image exposure section is , when the standby position is set to a position that is smaller than the conveyance distance required to eject the scanned original at the predetermined position, the first original that is being ejected is continuously ejected before at least the first scan exposure is completed. The third document is conveyed to the standby position before the scanning of the set number of copies is completed, and this operation is repeated thereafter.

Further, the automatic document feeder according to the present invention has: (1) a document feed inlet and a document ejection port on the document table glass are provided in different directions; (2) a document copy reference is provided on the document ejection side; Complete the paper feeding and paper ejection operations, and ■ Feed the paper during image exposure.The leading edge of the next document should be near the top edge of the platen glass.
The present invention is characterized in that it stands by on the upstream side of the pressing position of the conveyor belt, and is configured such that the ejecting operation of the preceding document is completed during image exposure.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 is a block diagram of an image forming apparatus (for example, an electrophotographic copying machine) equipped with an automatic document feeder according to the present invention. In the figure, a copying machine main body 100 is composed of a scanning exposure section A1 an image forming section B1 a paper feeding section C1 a conveying section E1 a fixing section F1 a paper discharging section G1 and a paper discharging tray H. In the figure, the broken line indicates the conveyance path of the recording paper P.

FIG. 2 is a configuration diagram showing the document conveyance path of the automatic document feeder that can swing open and close on the top surface of the copying machine main body 100, and FIG. 3 shows the drive system (power transmission system) of the automatic document feeder. FIG. 4 is a perspective view showing the document conveyance system and drive system inside the apparatus, and FIG. 5 is a plan view of the main parts of the automatic document conveyance device. Further, FIG. 6(A) is a schematic diagram showing the document conveyance path. The illustrated devices are automatic document feeders (RADF) with an automatic document reversing function.

First, the structure and operation of the automatic document feeder will be explained with reference to FIGS. 2, 4, 6, and 6(A).

A document placement table 11 is provided on the upper left side of the paper feed slO of the automatic document feeder, and allows documents to be stacked on top of each other.

A document setting solenoid SDI and a document leading end stopper 12 that can be swung by the solenoid SDI are provided below the leading end of the document placing table 11. With the upper end of the leading edge stopper 12 protruding near the leading edge of the document mounting table 11, the document stack is placed on the document mounting table 11, and the leading edge of the document stack is brought into contact with the document leading edge stopper 12. Arrange the paper.

When the document stack is placed on the document placement table 11, the presence or absence of the document on the document placement table is detected by the document set detection sensor (W document zero sheet detection sensor) PS2.
ADF mode is displayed on the control panel.

A width regulating plate 13.13 is provided on the document mounting table 11 to regulate the width direction of the document.

The width regulating plate 13 is connected to rack gears 14B and 14B that can alternately slide laterally across a pinion gear 14B on the lower surface of the document table 11, and is movable symmetrically about the center. The rack gears 14B, 14B are connected to width regulating plates 13, 13, respectively, and the amount of movement thereof is detected by a document size detection sensor PS1, so that the width size of the document can be read. Based on this read value, the length of the standard size document is automatically converted.

Therefore, by placing a stack of originals on the original placing table 11 and sliding the width regulating plate 13.13 so that it comes into contact with the width of the original, the various original sizes, that is, the lengths of each original, can be stored. A pickup roller 15 is located above and near the tip of the document table 11 and is movable up and down by the operation of a paper feed solenoid (latch plastic) SD2 and spring pressure, and is also moved by the driving force of a drive motor Ml. It is rotatable. By operating the copy button on the control panel of the copying machine main body 100, the automatic document feeder is started, the paper feed solenoid SD2 is energized and operated, and the pickup roller 15 connected thereto is lowered to feed the document. It comes into pressure contact with the top surface of the bundle, and at the same time begins to rotate by the driving force of the drive motor M1, and the document is sent out.

On the document feeding downstream side of the pickup roller 15, there is provided a paper separation means consisting of a feed belt 17 that rotates around a feed roller 16A and a driven roller 16B, and a double feed prevention roller 18 located below the feed belt 17. It is. The separation/feeding means transmits the driving force of the drive motor M1 to the electromagnetic clutch 2 through the electromagnetic clutch 2, and separates only the uppermost original among the plurality of originals sent out by the pickup roller 15. send out.

A document passage detection sensor PS3, an intermediate conveyance roller 25, and a curved guide plate 26 are provided on the document feeding downstream side of the separation sheet feeding means.

The passage of the leading edge of the original sheet sent out by the separation sheet feeding means is detected by the original passage detection sensor PS3, and is then fed by a pair of intermediate conveyance rollers 25 in the vicinity, passing between the guide plates 26. will be delivered. When the leading edge of the document passes a document passage synchronization sensor (reversed document passage detection sensor) PS5 disposed in the middle of this feeding path, a detection signal is generated to control document conveyance. The document passage synchronization sensor PS5 is connected to a document stopper 102, which will be described later. 2. Drive motor Ml and paper feed clutch. The operation of the first transport latch is controlled via a clock timer.

Next, in the transport section 30, the rotating transport bell 1-3
1 and a document platen glass (hereinafter referred to as document platen glass) 101 for exposing the original image on the top surface of the copying machine main body 100, and is conveyed while being pinched between the document platen glass 101 and the document stopper solenoid (latch).
Due to the operation of SD3, the document stops at the position where the leading edge of the document abuts the document stop/bar 102 which is protruding from the upper surface of the left end of the document platen glass 101.

The conveyor belt 31 includes a conveyor belt drive roller 32, a driven roller 33, three document holding rollers 34A and 34B,
34C, and is stretched between tension rollers 35.

The original plate is exposed to light by an exposure lamp 103 inside the copying machine main body at a stop position above the original platen glass, and the lens,
A document image is formed on a recording medium by scanning of a scanning exposure section A consisting of a mirror or the like.

Then, the same exposure is repeated for the set number of copies, and when a series of copying processes for the original is completed, the abutting portion of the original stopper 102 touches the original platen glass 10.
The leading edge of the original is released by retracting from the upper surface of the document 1, and the original is transported out by the conveyor belt 31 and the pair of paper ejecting rollers 41, which start rotating again, and passage of the trailing edge of the original is detected by the original ejecting detection sensor PS4. Thereafter, the document is discharged and placed on a paper discharge tray (original paper discharge tray) 42.

Furthermore, this automatic document feeder is provided with a document reversing section 50 for reversing the front and back of the document through the document reversing path. The document reversing unit 50 includes a transport roller group 51.52.5.
3, a guide plate 54, and an inverted original passage detection sensor PS5 for detecting an original passing through the inversion section 50.

Next, the power drive system for the roller group and belt will be explained with reference to FIGS. 3, 4, and 5.

The drive motor Ml is a servo motor that integrates a DC motor and a speed control device (encoder, tough generator, etc.). A toothed pulley P1 that is integral with the drive shaft 20 of the drive motor M1, and a toothed pulley P that is fixed to the intermediate shaft 21.
A toothed bell) Bl is stretched between each of the booms 2 and 2, and the intermediate shaft 21 is rotated by the driving rotation of the motor Ml.

On the intermediate shaft 21, in addition to the toothed pulley P2, a toothed pulley P3. P4 and electromagnetic clutch Kl are shaft-locked. The toothed pulley P3 and the conveyor belt drive C-ra3
Between both pulleys, a toothed pulley P5 fixed to the shaft end of the toothed bell 1-B2 is wound and meshed to be rotatable.

Due to the rotation of the conveyance belt drive roller 32, the driven roller 33 is also rotated via the conveyance belt 31.

Further, a toothed belt B3 that winds around the outer periphery of a toothed pulley P4 provided on the intermediate shaft 21 and meshes with the feed roller 1
A toothed pulley P6 is attached to the shaft end of a feed roller shaft 22 that rotates the feed roller 6A via gears Gl and G2, and a toothed pulley P6 is attached to the shaft end of an intermediate conveyance roller shaft 23 that is integral with the intermediate conveyance roller 25. Wrap around each outer tooth of toothed pulley P7.
They fit together. Note that R1 and R2 are the toothed belt B3 mentioned above.
This is a tension roller that is placed under tension while circumscribing the outer circumferential surface of the roller.

Due to the rotation of the toothed belt B3, the feed roller shaft 22, which is integral with the toothed pulley P6, rotates the feed roller 16A via the gears Gl and G2. The belt 17 is rotated, and the toothed pulley P8. The pickup roller 15 is rotated by P9 and the toothed belt B4. On the other hand, an electromagnetic clutch 2 is attached to the other end of the feed roller shaft 22, which is controlled based on an input signal I to rotate the feed belt 17 and pickup roller 15 to feed the original.

A paper discharge section 40 is provided on the conveyance downstream side of the driven roller IO. The paper discharge roller 41 is rotatably mounted on an axis. The paper discharge roller 41 is moved by gear G3. G4. Power is transmitted through G5 to rotate. Reference numeral 41A denotes a driven roller that is in pressure contact with the paper ejection roller 41 and rotates as a result.

When copying a double-sided original, the transport belt driving roller 32 starts rotating counterclockwise in synchronization with the completion of exposure of the original whose first side has been exposed through the process described above.
31 to the right on the document table glass 101. The right end portion of the transported document is sent to the document reversing section 50. Therefore, the document tray is conveyed around the document reversing section 50 along the guide plate 54 while being sequentially nipped by the conveyance rollers 51, 52, 53, and then the right end of the document tray, that is, the leading edge in this case, is placed on the document platen glass. 101, but before that, the rotation of the conveyor belt drive roller 32 is again switched clockwise based on the signal from the document passage detection sensor PS5 in which the leading edge of the document is reversed.

The above is a schematic configuration of the drive system to which power is transmitted by the drive motors Ml and M2.Next, the operation of the drive system will be explained. Figures 6 (B) and (C) are schematic diagrams showing the document feeding and conveyance process, Figure 7 is a diagram showing the rotational speed of each paper feed roller by the drive system, and Figure 8 is a block diagram of the drive system. 9 are time charts when three sheets of originals are automatically conveyed.

All these controls are performed by the CPU.

(2) When a stack of originals is stacked on the original table 11 and hits against the original leading edge stopper 12 which is stopped at the raised position, the original set detection sensor PS2 detects the presence or absence of the original and the ADF mode is set.

(2) When the width regulating plate 13 is moved and brought into contact with the width side edge of the document bundle, the document size detection sensor PSl detects the document width, and the CPU converts and stores the document length.

(2) When the copy button is pressed, a copy start signal is input, and the copying machine main body 100 and automatic document feeder are activated.

Clock timer t5.
t6. t7. t8. t9. tlO starts at the same time. Clock timer t6. t7 is document stopper solenoid S
After setting D3, clock timers t5 and tll actuate the reset of the solenoid SD3. Further, the clock timer t8 issues an OFF signal of 1 to the transport latch and a start signal for the drive motor M2. Furthermore, a clock timer t9. tlO and t14 are drive motor Ml
Controls ON/OFF of.

(2) This ADF activation signal applies voltage to the document setting solenoid SDI, and lowers the tip of the document tip stopper 12. At the same time, a voltage is applied to the paper feed solenoid SD2, and the pickup roller 15 descends to press the top layer of the document bundle.

(2) At the same time, when the drive motor Ml starts driving, the toothed pulley P1 on the motor drive shaft 20 rotates, and the intermediate shaft 21 having the toothed pulley P1 is rotated via the toothed belt Bl. At this time, both the electromagnetic gears Gl and G2 are in the ON state, and the rotation of the toothed belt B3 drives and rotates the feed roller shaft 22, causing the gears Gl and G2 to rotate.
．． The feed belt 3 is rotated via the feed roller 16A, and then the pickup roller 1 is rotated by the toothed belt B4.
5 is also rotated. At the same time, the toothed pulley P7 meshing with the toothed bell 1-83 is also rotated, and the intermediate conveying roller shaft 23
is rotated, and the intermediate conveying roller shaft 25 is in a rotating state.

At the same time, the toothed belt B2 wound around the intermediate shaft 21 rotates the conveyor belt drive roller 32 having the toothed pulley P5. As a result, the conveyor belt 31 wound between the roller 32 and the driven roller 33 is rotated. In addition, at this time, the pickup roller 15, the feed belt 17, the intermediate conveyance roller 25, and the conveyance bell 1-31
Each circumferential speed is high-speed conveyance mode v+ (for example, circumferential speed v
1=1200m+n/5ee).

Due to the rotation of each of the rollers and the rotation of the belt, the document placement table 11
The uppermost document DI of the upper document bundle is sent out by the pickup roller 15, and is separated by the feed belt 17 and double-feed prevention roller 18 to become the first document D in the uppermost layer.
I is fed separately.

■ When the leading edge of the document DI that has been separated and fed passes the document passing detection sensor PS3, a leading edge passing signal is generated, the clock timer starts measuring time from the generation of this signal, and after timing t3, the paper feed clutch is activated. Turn 2 off. As a result, after the leading edge of the document DI passes through the nip position of the intermediate conveyance roller 25, the driving rotation of the pickup roller 15 and the feed belt 17 is stopped, and the driving rotation becomes driven rotation.

■ The intermediate conveyance roller 25 continues to be driven and rotated to transport the document D.
I is fed, passes the document passage synchronization sensor PS5, and then the conveyance bell in the rotating state! -31 and slides on the document table glass lot.

■ Timed from the time the original passes through the synchronization sensor PS5.
After 6, the document stopper solenoid SD3 is activated, and the document stopper 102 projects to the upper surface of the left end of the document table glass 101. This solenoid SD3 is a latch type, and even if the power is turned off, the suction state is maintained unless reset.

■ At a time before the leading edge of the document reaches the document stopper 102, that is, after t9 measured from the time when the document passes by the synchronization sensor PS5, the drive motor M1 is temporarily turned off and the brake is applied to stop the document. . However, due to inertia, each moving part continues to operate to some extent, and the document continues to be transported. Does this motor brake short-circuit both terminals of motor M?
Methods such as applying a reverse voltage are effective.

[Phase] Then, at approximately t8, the transport latch Kl is turned off.
F and controls the conveyor belt 31 to stop the conveyor belt 31. However, even here, the conveyance belt 31 moves while being decelerated due to the inertia of the conveyance system, but since the document has the document stopper 102, the document hits the document stopper 102 and stops.

Also, almost simultaneously with this time measurement t8, the clock is switched from high speed to low speed.

■ When the original is stationary in this image exposure section (original table glass 101), the optical system 10 on the copying machine main body 100 side
3 starts scanning exposure.

(2) At timing tlO, turn on the paper feed clutch 2 and drive the drive motor Ml. As a result, the pickup roller 15 and the feed belt 17 start feeding the next document D2.

During the scanning exposure, the next original D2 is sent out and fed through the feed belt 17 and the intermediate conveyance roller 25, and when the leading edge of the next original D2 passes the original notification detection sensor PS3, a detection signal is generated and a clock timer is activated. By time measurement t (or pulse counting by a counter), this original document D2 is stopped and waited at a predetermined position S. This manuscript D2
The stop position S of the leading edge is on the upper surface of the document table glass lot, and a timer or pulse count is set upstream in the paper feeding direction from the pressing position by the document holding roller 34A near the document feeding port. During this time, the electromagnetic clutch 2 for feeding is ON and the electromagnetic clutch 1 for transport is OFF, so the preceding original document D1 being exposed is in a stopped state, but the subsequent original document D2 is in the low-speed transport mode V during this time.
2, the leading edge reaches a standby position S near the document table glass 101 and is temporarily stopped. However, the operation during this time should be completed at least after the end of scanning and before the restart signal is generated at V2 (for example, v -=
500mm/5ec).

The above-described subsequent document standby position #S is set differently depending on various document sizes, that is, the length of the document in the conveyance direction.

FIG. 6(B) is a schematic diagram showing the process of feeding and conveying the preceding original DI and the succeeding original D2.

When the leading edge of the subsequent document D2 passes the document passage detection sensor PS3, time measurement by the tarok timer is started, and after t2, the paper feed clutch 2 is turned OFF and paper feeding is stopped. Next, the leading edge of the document D2 is connected to the document synchronization sensor P.
Time measurement by the clock timer from the time of passing S5 t
After lJ, the driving of the drive motor M is stopped. Note that the leading edge of the document D2 at the standby position S is located near the document table glass 101 and is not in pressure contact with the conveyor belt 31, so it is close to the trailing edge of the preceding document at a short distance.

[Phase] Next, at the end of the scanning exposure, an ADF start signal is issued from the copying machine main body 100, and the first document DI is ejected and the second document D2 is fed. That is, the drive motor Ml is turned on, and the electromagnetic clutch K for conveyance is turned on.
By turning on l, the preceding document D1 is transferred to the conveyor belt 1-31.
The paper is conveyed by the paper delivery unit 40 and sent to the paper discharge section 40 . At the same time, the drive motor M2 is also turned on, driving and rotating the paper ejection roller 41, and rotating it in pressure contact with the driven roller 41A, so that the preceding document DI
is conveyed toward the paper discharge tray 42. At the same time, the subsequent document D2 is moved from the standby position S to the document holding rollers 34A, 34B, on the document table glass 101 in high speed mode v1.
The document slides while being held between the rotating conveyor belt 31 and the document table glass 101 due to the pressure contact of the document 34C, and reaches the document stopper 102 in the same manner as the stopping operation described above, thereby completing the document exchange.

At this time, the document is transported in the high-speed transport mode v1 when the clock timer t8 is counted, and after the clock timer t8 has been counted, the original transport mode is switched to the low-speed transport mode v2. After the time t8 is counted, 1 is turned off in the transport latch, and at the same time, the paper ejection drive motor M2 is switched to low speed v3, starts the exposure operation, and transports the preceding document DI at a low speed to send it out to the paper ejection tray 42. When the trailing edge of the preceding document DI passes the document ejection detection sensor PS4, the timer t15 starts counting after the time for the document Di to pass the paper ejection roller 41 based on the detection signal, and the drive motor M2 is turned off. . At this time, the low speed V3 of M2 is set so that the ejection operation of the document DI that is being ejected is completed before the exposure of the first copy of the next document D2 is completed.

In addition, in this embodiment, two motors Ml, M2 and 2
The above paper is fed to the electromagnetic clutch Kl by 2.

Although three drive systems for conveyance and paper ejection are controlled and operated, it is also possible to perform similar operations using three motors and one electromagnetic clutch. It is also possible to use one motor and three clutches.

Also, when copying a double-sided original, when the original is reversely fed and reversed to the original reversing unit 50 and then transported to the original platen glass again, timing starts from the detection of passage of the reversed original passage detection sensor PS5, and the original is processed in the same manner as described above. A similar effect can be obtained by setting the temporary stop position S.

Furthermore, since the present invention controls the ejection completion of the preceding original and the standby for the start of feeding of the next original during the scanning exposure of the original, it is possible to control large-sized originals or multiple copies that require time for scanning exposure. In the case of copy mode, by setting these copy modes and controlling the CPU, low-speed paper feeding and paper ejection is also possible.

This becomes more effective in stabilizing separation performance during document feeding, preventing damage to the leading edge of the document, stabilizing document feeding performance, and preventing scattering of ejected documents.

[Effects of the Invention] As described above, according to the automatic document feeder of the present invention, not only is it possible to shorten the document feed time, but also stabilization and improvement of separation performance can be achieved by low-speed separation during document feeding. This is effective for smoothing the document transport and preventing damage to the leading edge of the document. In addition, since no more than three originals are operated at any time, it is possible to reduce the load on the motor, save power consumption, and install a small, low-torque motor to prevent noise.

In particular, the document transport is controlled by starting motors, clutches, solenoids, and various timers based on the ADF stat signal from the copying machine body, and in response to optical scanning, so the control of 70g is simple and clear. ,
This has the advantage that there are fewer causes of malfunctions and manufacturing costs can be reduced.

Furthermore, since the ejection operation can be performed independently and at low speed, the alignment of ejected sheets is stabilized. Furthermore, since three or more originals are not operated at the same time, jam handling is also easy.

[Brief explanation of drawings]

1 is a block diagram of an automatic document feeder divided by an image forming apparatus according to the present invention, FIG. 2 is a block diagram showing the document feed path, and FIG. 3 is a block diagram showing the drive system (power transmission system) of the automatic document feeder. )
FIG. 4 is a perspective view showing the document conveyance system and drive system inside the apparatus, FIG. 5 is a plan view of the main parts of the automatic document conveyance device, and FIGS. 6(A), '(B), (C) is a schematic diagram showing the document conveyance process, FIG. 7 is a diagram showing the rotational speed of each paper feed roller by the drive system, FIG. 8 is a block diagram of the drive system, and FIG.
The figure is a time chart of the document feeding and conveying process. lO...Paper feed section 11...Original mounting table)
5...Pickup roller 17...Feed belt 18...Double feed prevention roller 25...Intermediate conveyance roller 30...Conveyance section 31.
...Transport belt 32...Transport belt drive roller 33...Followed rollers 34A, 34B, 34C...Document holding roller 40...
- Paper ejection section 41... Paper ejection roller 42...
Paper ejection tray 50... Original reversing unit 100...
Copying machine main body 101...image exposure section (original table glass) 102...
Document stopper 103...Exposure lamp A...Scanning exposure unit Kl...Electromagnetic clutch for paper feeding 2...Electromagnetic clutches for transport Ml, M2...Drive motor D...Document Dl... Preliminary manuscript D2.
D3. D4...Subsequent original PSl...Original size detection sensor PS2...Original set detection sensor PS3...Original passage detection sensor PS4...Original discharge detection sensor PS5...Original synchronization sensor S... Subsequent document standby position vl...High speed transport mode v2...Low speed transport mode

Claims (1)

[Claims] The originals are separated one by one from the stack of originals stacked on the original platen and fed one by one to the image exposure section.The originals are stopped at the image exposure section, and the optical system is moved to perform scanning exposure and exposure. In an automatic document feeder that later transports the document to a document ejection table, a paper feeding unit that feeds the document to the image exposure section;
A conveyance means for conveying and stopping the original to a predetermined position of the image exposure section, a paper ejection means for conveying the original after exposure, and a control means for driving and controlling these means, the paper feeding means and the conveyance means , a paper ejecting means, and a control means, the conveying means stops transporting the first original from the original placing table to a predetermined position of the image exposure section, and while scanning exposure for a predetermined number of copies is performed, the next original is transferred to the original placing table. The document is conveyed to a position further downstream and upstream of the document being scanned and exposed, and a standby operation is completed, and then an operation is started to discharge the first document that has been scanned from the image exposure unit, and at the same time, the document is conveyed to a position further downstream than the document being scanned and exposed. The conveyance of the second original document that had been previously scanned is stopped until it reaches a predetermined position in the image exposure section, and the conveyance distance from the standby position to the predetermined position in the image exposure section is determined by the conveyance distance required until the scanned document at the predetermined position is ejected. When the standby position is set to a smaller position, at least 1
Before the completion of copy scan exposure, the first document which is being ejected is continuously ejected, and before the set number of copies has been scanned, the third document is conveyed to the standby position and the standby operation is completed, and this operation is continued thereafter. An automatic document feeder characterized by repeating the following steps.