JPH0388656A - Automatic document conveyer - Google Patents

Abstract

PURPOSE:To avoid generation of picture dislocation, when a copy picture is formed, while increasing a copy speed of a total unit by performing action of lowering a document stopper before completion of at least scanning exposure action of the final copy. CONSTITUTION:A plurality of sheet documents are conveyed successively to a picture exposure part and stopped in a predetermined position by a document stopper 102 in the picture exposure part, and an optical system is moved to perform scanning exposure with the document carried out after the exposure to a document discharge table 14. Here action of lowering the document stopper 102 is performed before completion of at least scanning exposure action of the final copy. In this way, generation of picture displacement by impulse vibration due to driving the document stopper 102 can be impeded while being possible to increase a copy speed of the total unit.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in an automatic document feeder in a recording apparatus such as an electrophotographic copying machine.

[Background of the invention]

The automatic document feeder generally uses f
Use it by attaching it to the rL platen glass. 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 a predetermined number of copies 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. Furthermore, when obtaining a large number of copies from an original, the W and stack are transported after the scanning exposure of the final copy is completely completed. 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 the automatic document feeder to automatically feed and eject documents onto the document table, the necessary operations are performed during the exposure time or during the return time of the scanning optical system. For example, copy productivity is 100% and no wasted time is required.

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, if the document transport speed is increased, the document will be driven at a constant transport speed due to friction between the document and the platen glass, etc.; therefore, it will be difficult to always stop the document at a predetermined position, and jams etc. Cause. In addition, various problems arise, such as an increase in the size of the motor, an increase in power consumption, an increase in the degree of document damage, and a decrease in document separation performance.

[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 sequentially transports a plurality of sheet-like originals to an image exposure section, stops the documents at a predetermined position in the image exposure section by a document stopper, and operates an optical system. In an automatic document feeder that moves to perform scanning exposure and transports the document to a document eject table after exposure, the document stopper is lowered at least before the scanning exposure operation for the final copy is completed. That is.

In addition, when making two or more copies from the double document, the automatic document feeder of the present invention is configured to perform an optical system return process before the optical system return process that scans and exposes the final page of the document, and during the optical system return process when making each copy. The present invention is characterized in that the document stopper is lowered at any time.

〔Example〕

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

FIG. 1 shows the constituent countries of the document transport path of the automatic document feeder according to the present invention, and FIG. 2 shows the drive system of the automatic document feeder (
FIG. 3 is a perspective view showing the document conveying system and drive system inside the apparatus, and FIG. 4 is a plan view of the main parts of the automatic document conveying apparatus. Furthermore, FIG. 5 is an external perspective view of the upper part of the copying machine equipped with an automatic document feeder. Figure 6 (
A) is a schematic diagram showing a document conveyance path. Note that these illustrated devices are automatic document feeders with an automatic document reversing function (
RADF).

First, the structure and operation of the automatic document feeder will be explained with reference to FIGS. 1, 3, 5, and 6A.

A document placement table l is provided on the left side of the upper surface 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 edge stopper ID swingable by the solenoid SDI are provided below the tip of the document placing table l. With the upper end of the leading edge stopper ID protruding near the leading edge of the document mounting table L, place the document stack on the document mounting table L, and abut the leading edge of the document stack against the document leading edge stopper ID. Arrange the paper.

When a stack of originals is placed on the original platen l, the presence or absence of originals on the original platen is detected by the original set detection sensor (zero original detection sensor) PS2, and the ADF mode is displayed on the control panel 110 of the copying machine main body 100. is displayed.

Width regulating plates IA, IA are provided on the document mounting table l to regulate the width direction of the document. The width regulating plate IA is formed by rack gears IA that can alternately slide laterally across the pinion gear IB on the lower surface of the document table 1.
C and IC, respectively, and can be moved symmetrically around the center. The rack gears ic and tc are connected to width regulating plates IA and IA, respectively, and the amount of movement thereof is detected by a document size detection sensor PSI, 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, place the document stack on the document placement table 1, and press the width regulating plate IA.
, IA is slid and brought into contact with the width of the document, so that various document sizes, that is, the lengths of each document are stored.

A pickup roller 2 is located above and near the tip of the document table L, and is movable up and down by the operation of a paper feed solenoid (latch type) SD2 and spring pressure, and is also rotatable by the driving force of a drive motor M. ing. By operating the copy button Ill on the control panel 1.10, the automatic document feeder is started, the paper feed solenoid SD2 is energized and operated, and the pickup roller 2 connected thereto is lowered to remove the document bundle. At the same time, the document starts to rotate by the driving force of the drive motor M, and the document is sent out.

On the document feeding downstream side of the pickup roller 2, there is a feed belt 3 that rotates around a feed roller 3A;
Separation sheet feeding means consisting of a double feeding prevention roller 4 located below is provided. The separation sheet feeding means is driven by a drive motor M.
The driving force is transmitted to the electromagnetic clutch 2 through the pickup roller 2, and only the uppermost original among the plurality of originals sent out by the pickup roller 2 is separated and sent out.

On the document feeding downstream side of the separation sheet feeding means, a document passage detection sensor PS3, an intermediate conveyance roller 5, and a curved guide plate 6 are provided.
is the provision.

The passage of the leading edge of the original sheet sent out by the separation feeding means is detected by the original passage detection sensor PS3, and is then fed by a pair of intermediate conveyance rollers 5 in the vicinity, passing between the guide plates 6. will be delivered. When the leading edge of the original passes through the original passage synchronization sensor (inverted original passage detection sensor) PS5 located in the middle of this feeding path,
Emit a detection signal to control document transport. The document passage synchronization sensor PS5 is connected to a document stopper 102, which will be described later. 2. Drive motor M and paper feed clutch. The operation of the transport latch K1 etc. is controlled via a timer.

Next, the rotating conveyor belt 8 and the copying machine main body 1.0
0 is conveyed while being pinched between the original platen glass for exposing the original image on the upper surface (hereinafter referred to as the original platen glass) 101, and is projected from the upper surface of the left end of the document platen glass 101 by the operation of the document stopper solenoid (latch type) SD3. The document stops at a position where the leading edge of the document abuts the document stopper 102 which is set to .

The conveyance belt 8 is stretched between a conveyance belt drive roller 9, a driven roller 10, three document pressing rollers 11, and a tension roller 12.

The original is exposed to light by an exposure lamp 103 inside the copying machine main body at a stop position on the original glass platen, and the lens,
A W striped image is formed on the recording medium by scanning with an optical system including a mirror or the like.

The same exposure is repeated for the set number of copies, and when the series of copying processes for the original is completed, the abutting portion of the original stopper 102 is pressed! 8 glasses 10
1, the leading edge of the original is released, and the original is conveyed out by the conveyor belt 8 and the pair of paper ejection rollers 13, which start rotating again, and passage of the trailing edge of the original is detected by the original ejection detection sensor PS4. Thereafter, the document is discharged and placed on a paper discharge tray (original paper discharge tray) 14.

Furthermore, this automatic document feeder is provided with a document reversing section 30 for reversing the front and back of the document using the document reversing path. The document reversing unit 30 includes transport roller groups 31, 32.3.
3, a guide plate 34, and an inverted original passage detection sensor PS5 for detecting an original passing through the inversion section 30.

Next, the power drive system for the roller group and belt will be explained with reference to FIGS. 2, 3, and 4.

The drive motor M is a servo motor that integrates a DC motor and a speed control device (encoder, tacho generator, etc.). A toothed pulley Pl that is integral with the drive shaft 20 of the servo motor M, and a toothed pulley P2 that is fixed to the intermediate shaft 2i.
A toothed belt Bl is stretched between the respective booms, and the intermediate shaft 21 is rotated by the drive rotation of the motor M.

On the intermediate shaft 21, in addition to the toothed boolean IJ P2, a toothed 7-ri P3. 1 is pivotally attached to P4 and the electromagnetic clutch. A toothed belt B2 is wound and meshed between the toothed boolean U P 3 and a toothed pulley P5 fixed to the shaft end of the conveyor belt driving roller 9, so that the toothed belt B2 can rotate. ing.

The conveyor belt 8 is rotated by the rotation of the conveyor belt drive roller 9.
The driven roller IO rotates via the driven roller 10, and the toothed pulley PIO fixed to the shaft end of the driven roller 10 meshes with the toothed pulley pH via the toothed belt B5, thereby rotating the paper discharge roller 13.

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 3
A toothed pulley P6 is attached to the shaft end of the feed roller shaft 22 which rotates A via the gear Gl, Wrap around each outer peripheral tooth of the attached toothed gooley P7.
They fit together. Note that R1 and R2 are the toothed belt B3 mentioned above.
This is a tension roller that circumscribes the outer peripheral surface of the roller and forms a tension film.

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 3A via the gears Gl and G2.
Rotate the feed belt 3 wound between P8.B and the toothed pulley P8.B. With P9 and toothed belt B4,
Rotate the pickup roller 2. 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 to rotate the feed belt 3 and pickup roller 2 to feed the original.

During duplex original copying, the conveyor belt drive roller 9 starts rotating counterclockwise in synchronization with the completion of exposure of the document whose first side has been exposed in the above-described process, so that the conveyor belt 8
The document is conveyed rightward on the document table glass 101 by the document table glass 101.

The right end portion of the transported document is sent to the document reversing section 30. Therefore, the original @D is conveyed around the inside of the document reversing unit 30 along the guide plate 34 while being sequentially nipped by the conveyance rollers 31, 32, 33, and then the right end of the document tray, that is, the leading edge in this case, is placed on the document table. Before the document is sent out onto the glass 101, the rotation of the conveyor belt drive roller 9 is switched clockwise again based on a signal from the document passage detection sensor PS5 in which the leading edge of the document is reversed.

The above is a general configuration of the drive system to which power is transmitted by the drive motor M. Next, the operation of the drive system will be explained. Figures 6 (CB) 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 brochure diagram of the drive system. , FIG. 9 is a time chart.

(2) When a stack of originals is stacked on the WC stacking table 1 and hits against the original leading edge stopper ID 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 plates IA, IA are moved and brought into contact with the width side edges of the document bundle, the document size detection sensor PSl detects the document width, and the CPU converts and stores the document length.

■ After setting the required number of copies using the number of copies setting key 112, press the copy button 111.
A copy start signal is input, and the copying machine main body 100 and automatic document feeder are activated.

■ This ADF activation signal applies a 1m voltage to the document set solenoid S D l and
Lower the tip of D. At the same time, a voltage is applied to the paper feeding lens SD2, and the pickup roller 2 descends to press against the top layer of the document bundle.

(2) At the same time, the drive motor M starts driving, and the toothed pulley Pl on the motor drive shaft 20 rotates, and the intermediate shaft 21 having the toothed boot U P I is rotated through the toothed belt Bl.
Rotate. At this time, electromagnetic clutches 1 and 2 are both in the ON state, and the feed roller shaft 22 is driven and rotated by the rotation of the toothed belt B3, and the gears Gl and G
2. The feed belt 3 is rotated via the feed roller 3A, and then the pickup roller 2 is rotated by the toothed belt B4.
is also rotated. At the same time, the toothed pulley P7 that meshes with the toothed belt B3 is also rotated, rotating the intermediate conveyance roller shaft 23, and the intermediate conveyance roller shaft 5 enters a rotating state.

At the same time, the toothed belt B2 wound around the intermediate shaft 21 rotates the conveyor belt drive roller 9 having the toothed pulley P5. As a result, the conveyor belt 8 wound between the roller 9 and the driven roller 10 is rotated. In this case, the circumferential speeds of the pick-up rotor 2, feed belt 3, intermediate conveyance roller 5, and conveyance belt 8 are all in high-speed conveyance mode v, (for example, circumferential speed v, = 1200
mm/5ee).

Due to the above-mentioned rotation of each roller and rotation of the belt, the top layer FtK DI of the document stack on the document placement table 1 is sent out by the pickup roller 2, and is separated by the feed belt 3 and the double feed prevention roller 4, and the top layer is The first original Di is separated and fed.

■ 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, and the timer starts timing from the generation of this signal.
After counting the time, turn off the paper feed clutch 2. As a result, the leading edge of the document DI passes through the nip position by the intermediate conveyance roller 5, and then passes through the picker/knob roller 2 and the feed belt 3.
The driving rotation of the motor stops and becomes driven rotation.

■ Subsequently, the intermediate conveyance roller 5 is driven and rotated, and the original fiD
1 is fed, passes the document passage synchronization sensor PS5, and then slides on the document table glass 101 while being pinched by the rotating conveyor belt 8.

■ Timed from the time the original passes through the synchronization sensor PS5.
6, the document stopper solenoid SD3 is activated and N
A document stopper 102 protrudes from the upper surface of the left end of the document table glass 101.

■ Measure the time from when the original passes through the synchronization sensor PS5 (
9, the drive motor M is temporarily turned off and stopped before the leading edge of the document hits the document stopper 102, and the motor brake is applied to cause the document to hit the stopper due to inertia. In this embodiment, the motor is turned off approximately 5 to 10 mm before the stopper, and the conveyance of the document is decelerated and stopped.

(2) Thereafter, at approximately t8, the conveyance latch Kl is turned OFF, and the conveyance belt 8 is controlled and stopped so that the original document stops at a position where it has slightly passed the stopper. Then, almost simultaneously, the clock is switched from high speed to low speed.

(2) Turn on the paper feed clutch 2 and drive the drive motor M at the timing tlo. As a result, the pickup roller 2
Then, the next document D2 is fed by the feed roller 3.

While the document is in a stationary state in the image exposure section, scanning exposure is performed on the document up to the number of copies set by the copy number set key 112 of the copying machine main body 100.

Then, the number of copies set by the copy number set key 112 on the main body is set on the counter of the copying machine main body, and each time a - number of copies is made, this counter counts, and copies are made up to the set number. , the copying machine itself detects the final copy. Then, at least at a timing slightly before the final exposure is completed, the original stopper 102 is lowered when the exposure optical system returns. That is, the document stopper 102 is reset. However, as shown in the time chart of FIG. 9, the reset operation of the document stopper 102 does not necessarily have to be performed a little before the exposure of the final copy is completed, but rather when the document stopper 102 is reset at the timing of the first copy or the first copy. It is sufficient that the optical system returns at a timing a little before the scanning exposure of each copy is completed, such as the return of the optical system after the completion of the scanning exposure of . That is, in FIG. 9, the reset operation X1 of the document stopper 102 may be performed on the return path of the optical system after the scanning exposure of the first copy is completed. Similarly, the document stopper reset operation X2 may be performed on the return path of the optical system after the scanning exposure of the second copy is completed. Furthermore, in this example, the document stopper reset operation X3 may be performed on the return path of the optical system after the scanning exposure of the third sheet, which is the final copy, is completed. However, please be careful because if you reset the document stopper 102 during scanning exposure for each copy, the vibration of the reset operation may cause the document to shift from the specified position, making it impossible to obtain a correct copy. The document stopper 102 must not be reset at this timing, that is, during scanning exposure (outward pass). By resetting the document stopper 102 when the scanning exposure optical system for copying has completed exposure and is returning, effective control can be achieved without wasting the next operation.

Then, before exposure or during scanning exposure, the next original D2 is sent out and fed through the feed roller 3 and intermediate conveyance roller 5, and when the leading edge of the next original D2 passes the original notification detection sensor PS3, a detection signal is issued and a timer Timing by t
(or by counting pulses by a counter), the document D2 is stopped at a predetermined position and kept on standby. 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 DI being exposed is in a stopped state, but the subsequent original document D2 is in the low-speed transport mode V during this time. , and the leading edge reaches the vicinity of the document table glass 101 and is on standby. However, the operation during this time is set at V2 (for example, v2 = 50
0mm/5ee) is determined.

The above-mentioned subsequent document standby position 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.

Timing by the timer starts when the leading edge of the subsequent document D2 passes the document passage detection sensor PS3, and (2
Afterwards, the paper feed clutch 2 is turned OFF and paper feeding is stopped. Next, the driving of the drive motor M is stopped after the timer has measured time tld from the time when the leading edge of the document D2 passes the document synchronization sensor PS5. In addition, the above-mentioned - time stop position [P
The leading edge of the document DI located at is located near the document table glass 101 and is not in pressure contact with the conveyor belt 8, so it is close to the trailing edge of the preceding document at a short distance.

■ Next, at the end of the scanning exposure, from the copying machine main body 100
A DF start signal is issued and the exposure operation for the second original is performed. That is, by turning on the drive motor M and turning on the electromagnetic clutch Kl for conveyance, the preceding document Di is conveyed by the conveyance belt 8, and is discharged and placed on the paper discharge tray 14 via the paper discharge roller i3. . At the same time, the subsequent document D2 slides from the standby position on the document table glass 101 and reaches the document stopper 102 in the stopping operation, thereby completing the W document exchange. At this time, the document conveyance according to the timer count of 8 is in the high speed conveyance mode v1.

■ Timer t5゜t by the above ADF start signal
6. t7. t8. t9. tlo starts at the same time. ri4-7-t6. t7 is document stopper solenoid SD
3, timer t5 and Ell actuate the reset of the solenoid SD3. Also, timer 18
emits an OFF signal for the transport station Kl. Furthermore, timer t9. tlO and t14 are drive motor M ON
, OFF is controlled.

The two-page original D2 is conveyed from the - time stop position P2 to the original platen glass 101 in the high speed mode v1, and the timer t
After it is temporarily stopped at 9, it abuts against the document stopper 102 due to inertia and stops. Thereafter, it is operated in the same manner as the preceding document Di, and is subjected to exposure processing and discharged.

In this embodiment, one motor and two electromagnetic clutches control and operate the two drive systems mentioned above, but it is also possible to perform similar operations using two motors and one electromagnetic clutch. It is.

Also, when copying a double-sided original, when the original is reversely fed and reversed to the original reversing unit 30 and then transported to the original platen glass again, the timing starts from the passage detection of the reversed original passage detection sensor PS5, and the original is processed as described above. A similar effect can be obtained by setting a temporary stop position.

〔Effect of the invention〕

As described above, according to the automatic document feeder of the present invention, not only is it possible to shorten the time to feed documents, but also the low-speed separation during document feeding improves the stabilization of separation performance and smoothes document feeding. This is effective in preventing damage to the leading edge of the document. In particular, when making multiple copies from an original, the original stopper evacuation operation for ejecting the original is performed before the scanning operation of the exposure optical system for the final copy is completed, increasing the overall copying speed and efficiency. Get better. In particular, since the document stopper is retracted during the return operation of the exposure optical system, impact vibrations for driving the document stopper do not cause image shift during copy image formation. Since these controls 1 can be achieved mainly by changing the control program for the entire ADF, they are simple and clear, have few causes of malfunctions, and have the advantage of reducing manufacturing costs.

[Brief explanation of drawings]

FIG. 1 shows the constituent countries of the document transport path of the automatic document feeder according to the present invention, and FIG. 2 shows the drive system of the automatic document feeder (
FIG. 3 is a perspective view showing the document conveying system and drive system inside the apparatus, and FIG. 4 is a plan view of the main parts of the automatic document conveying apparatus. Furthermore, FIG. 5 is an external perspective view of the upper part of the copying machine equipped with an automatic document feeder. Figure 6 (
A), (B). (C) is a schematic diagram showing the document transport process, Figure 7 is a diagram showing the rotational speed of each paper feed roller by the drive system, Figure 8 is a block diagram of the drive system, and Figure 9 is the document feed and transport process. This is a time chart. l...Document mounting table 1A...Width regulation plate IB
...Pinion gear 1c...Rack gear LD...
・Document leading edge stopper 2...Pickup roller 3...Feed belt 3A...Feed roller 4...Double feed prevention roller 5...Intermediate conveyance roller 6
... Guide plate 8 ... Conveyor belt 9 ...
Conveying belt drive roller 13... Paper ejection roller 14... Paper ejection tray 3
0... Original reversing section 31.32.33... Conveying roller group 34... Guide plate 100... Copying machine main body 101... Image exposure section (document glass) 10
2... Original stopper 110... Control panel 1... Copy button 112... Copy number setting keys Kl, K 2... Electromagnetic clutch (MC) M...
Drive motor D... Original DI... Preceding original
D2...Subsequent original PS1...-Original size detection sensor PS2...Original set detection sensor PS3...If' product passage detection sensor PS4...Original discharge detection sensor PS5...Reversed original passage detection sensor

Claims (2)

[Claims] (1) A plurality of sheet-like originals are sequentially conveyed to the image exposure unit, the originals are stopped at a predetermined position by a document stopper in the image exposure unit, the optical system is moved to perform scanning exposure, and after exposure, the originals are An automatic document feeder that transports a document to a document eject table, wherein the operation of lowering the document stopper is performed at least before the scanning exposure operation for final copying is completed. (2) When making two or more copies from the original,
Before the optical system return process that scans and exposes the final page of the document,
2. The automatic document feeder according to claim 1, wherein the document stopper is lowered at any time during a return stroke of the optical system when making each copy.