JPH0361239A - Automatic document transfer apparatus - Google Patents

Abstract

PURPOSE:To shorten the time of document transfer by variably setting an once stop position for the succeeding document sheet in accordance with a document size detection signal from a detecting means for detecting a size of a document sheet. CONSTITUTION:The feed of the succeeding document sheet is started before completion of exposure operation for the preceding document sheet, and the succeeding document sheet is once stopped for waiting at a predetermined position just before an image exposure section. Then, the once stop position for the succeeding document sheet is variably set in accordance with a document size detection signal from a detecting means PS1 for detecting a size of a document sheet, thereby it is possible to increase the capacity of managing document sheets to be copied.

Description

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

[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.

This automatic document feeder is installed; in a copying machine with a moving optical system, the automatic document feeder moves a sheet document (hereinafter referred to as the document) from the document tray (stack section) on which it is placed. The originals fed out one sheet at a time are fed onto the original table glass by a conveyor belt, where they are exposed to light by an exposure section lamp inside the main body of the copying machine, and then further conveyed onto the original document ejection table.

Conventionally, the operation of exchanging originals on the original platen glass by an automatic document feeder is such that after a paper ejection sensor detects that the original on the original platen has been ejected, the next original is sent out from the stack section and placed on the AM platen glass. It was then transported to a designated location 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]

Using an automatic document feeder to automatically feed and eject documents onto the document table *1
00% 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, increasing the document transport speed causes various problems 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 JK document conveying device of the present invention, which is distantly related to the above object, sequentially conveys a plurality of sheets [fa] to an image exposure section, and
In an automatic document feeder that stops the 41-fold stack at the image exposure section, moves the optical system to perform scanning exposure, and transports the document to the document eject tray after exposure, before the exposure operation for the preceding sheet document is completed. , the subsequent sheet 1-shaped FK product is started to be fed and temporarily stopped at a predetermined position in front of the image exposure section to stand by, in response to a document size detection signal from a detection means for detecting the size of the document. , the temporary stopping position of the subsequent document is set variably.

Further, the automatic document feeder of the present invention sets at least two subsequent document temporary stopping positions according to the document size, and sets the trailing edge of the preceding document and the trailing edge of the preceding document after the document is temporarily stopped. ! The present invention is characterized in that the temporary stop position is set such that the distance between the leading edge of the document and the conveyance path is reduced depending on the document size.

Further, in the automatic document feeder of the present invention, the speed of the document feeding operation to feed the document to the temporary stop position is yK on the image exposure section.
It is characterized by being lower than the transport speed.

〔Example〕

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

FIG. 1 is a block diagram showing the document conveyance path of the automatic document feeder according to the present invention, and FIG. 2 is a diagram showing the drive system of the automatic document feeder (
FIG. 3 is a perspective view showing the document conveyance system and drive system inside the apparatus, and FIG. 4 is a plan view of essential parts of the automatic document conveyance device. 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 conveyance process. 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 FIG. 1, FIG. 5, and FIG. 6(A).

A cost placement table l is provided on the upper left side of the automatic document feeder, and allows one or more documents to be placed at a predetermined position.

When the document stack is placed on the document placement table l, the presence or absence of the document on the document placement table is detected by the document set detection sensor (zero document detection sensor) PS2, and the ADF mode is displayed on the control panel 110.

Width regulating plates IA, IA are provided on the document mounting table l to regulate the width direction of the document. This width regulating plate IA is connected to the rack gears 1c and IC which can alternately slide horizontally across the pinion gear 1B on the lower surface of the YTC document table l, and is movable symmetrically around the center. There is. This rack gear 1c, I
c is connected to the width regulating plates IA and IA, 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 l and sliding the width regulating plates lA, IA so that they come into contact with the width of the originals, various original sizes, that is, the lengths of each original are memorized.

Next, by operating the copy button Ill, the pickup roller 2 is lowered using the lowering means and comes into contact with the top surface of the document bundle, and at the same time begins to rotate W, and the stack is sent out.

At the same time, the feed belt 3, which rotates around the feed roller 3A, which starts its driving rotation, cooperates with the double-feed prevention roller 4 located below the feed belt 3, so that only the uppermost document sheet is sent out.

The sent-out i-document is conveyed by a pair of intermediate conveyance rollers 5, passing between a curved guide plate 6 and passing through a document passage detection sensor PS3. Next, the original image (11) on the top surface of the copying machine main body is conveyed while being held under pressure between the rotating conveyor belt 8 and the exposure document glass (hereinafter referred to as the document glass) lot, and is projected from the top surface of the document glass 101. The document stops at the position where the leading edge of the document abuts the document stopper 102 which is in the current state.

The conveyor belt 8 includes a conveyor belt drive roller 9, a driven roller 1O, and 13 yrC document pushers 11. It is stretched between tension rollers 12.

The original is placed in duplicate at the stop position on the original platen glass 101.
The image is exposed by an exposure lamp 103 inside the machine body, and a W, fI4 image is formed on the recording medium by scanning with an optical system consisting of lenses, mirrors, etc.

When a series of copying processes for the original document is completed, the abutting portion of the g original stopper 102 is pressed against the original platen glass 101.
The leading edge of the original is retracted from the upper surface and the leading edge of the original is released, and the original is transported out by the conveyor belt 8 and the pair of paper ejecting rollers 13, which start rotating again.
The document is detected in S4 and is then discharged and placed on the paper discharge tray (original paper discharge table) 14.

Furthermore, this automatic document feeder is provided with a document reversing section 30 for reversing the front and back of the document W along the document reversing path. The document reversing unit 30 includes transport roller groups 31, 32 .
33, a guide plate 34, and a document passage detection sensor PS5 for detecting a document passing through the reversing section 30.

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

M is for DC motor and speed control equipment! i! It is a servo motor that integrates (encoder or tacho generator, etc.). A toothed belt Bl is stretched between the toothed pulley PI, which is integral with the drive shaft 2o of the servo motor M, and the toothed pulley P2, which is fixed to the intermediate shaft 21.
1 is rotated by the drive rotation of the motor M.

On the intermediate shaft 21, in addition to the toothed gooley P2, a toothed pulley P3. P4 and electromagnetic clutch Kl are shaft-mounted. The toothed pulley P3 and the conveyor belt drive roller 9
Between the toothed pulley P5 fixed to the shaft end of the
The toothed belt B2 is wound and meshed to be rotatable.

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

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.A is attached to the shaft end of the feed roller shaft 22 that rotates the feed roller shaft 22 through gears Gl and G2. The rollers are wound around and meshed with the outer peripheral teeth of a toothed pulley P7 which is rotatably attached to the shaft end of the intermediate conveyance roller shaft 23 which is integral with the intermediate conveyance roller 5. Note that R1 and R2 are tension rollers that are placed under tension in circumferential contact with the outer peripheral surface of the toothed bell 1-83.

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 document tray is conveyed around the document reversing section 30 along the guide plate 34 while being sequentially nipped by the conveyance rollers 31, 32, and 33; Before the document is sent out onto the glass lot, the rotation of the conveyor belt driving 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 schematic configuration of a drive system to which power is transmitted by the servo motor M. Next, the operation of the drive system will be explained. 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, FIG. 9 is a flowchart, and FIG. 1O is a time chart.

(2) When a stack of originals is stacked on the original fIR table l and abuts against the stopper 1D, the original set detection sensor PS2 detects the presence or absence of the original, and the ADF mode is set.

■ When the width regulating plates IA, IA are moved and brought into contact with the width side edges of the document stack, the document size detection sensor PS1 detects the document width, and the CPU converts and stores the document length.

(2) When the copy button ill is pressed, a copy start signal is input, and the pickup roller 2 descends to press the top layer of the document bundle.

■ Continuing to start driving motor M, motor drive shaft 2
The toothed pulley P1 on the top rotates to rotate the intermediate shaft 21 having the toothed pulley Pi via the toothed belt Bl.

At this time, both electromagnetic clutches (MC) K1 and 2 are ON.
state, the rotation of the toothed belt B3 drives and rotates the feed roller shaft 22, and the gears Gl, G2 .
The feed belt 3 is rotated via the feed roller 3A, and the pickup roller 2 is also rotated by the toothed belt B4. 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. At this time, the circumferential speeds of the pickup roller 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 1-1200 m).
m/5ee).

Due to the above-mentioned rotation of each roller and rotation of the belt, the top layer of the original among the stack of originals on the original placing table l is transferred to the pickup roller 2.
The document is sent out by the feed belt 3 and the double-feed prevention roller 4, and the topmost document is conveyed via the intermediate conveyance roller 5 and the guide plate 6, and then is pinched by the rotating conveyance belt 8. The document slides on the document table glass 101, and before the leading edge of the document hits the document stopper 102, the motor M is turned off and stopped, and the motor brake is applied to cause the document to hit the stopper due to inertial force.

In this embodiment, the motor is turned off approximately 5 to lQmm before the stopper.

(2) While the document is in a stationary state in this image exposure section, scanning exposure is started by the optical system on the copying machine main body side. At this time, the next original is fed before or during scanning exposure, is fed through the feed roller 3 and intermediate conveyance roller 5, and when the leading edge of the original passes the original notification detection sensor PS3, a detection signal is issued and a timer is activated. The document is stopped at a predetermined position and kept on standby by time measurement t (or pulse counting by a counter). During this time, the electromagnetic clutch 1 (2) for feeding is ON, and the electromagnetic clutch Kl for conveyance is OFF.
Therefore, although the preceding document [1] during exposure is in a stopped state, the subsequent document is fed in the low-speed transport mode v2 during this time, and its leading edge reaches the vicinity of the document table glass 101 and waits. ing. However, the speed of vz (for example, vz" 500 mm/5ec) is determined so that the operation during this time is completed at least after the end of scanning and before the restart signal is generated.

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. 11 shows originals of various sizes (B5-A3) with the original table placed on the lath 101 and pressed against the original stopper 102.
) is a plan view showing the stopped state.

Among the above four document sizes, in one embodiment of the present invention,
85 size, A4 size small size original, 84 size.

The manuscripts were roughly divided into two types: large A3 size manuscripts.

Figure 6 ('B) is the small size original (B5.A4) D
FIG. 3 is a schematic diagram showing the paper feeding and conveyance process of i. When the document size is detected by the document size detection sensor PS1 by operating the width regulating plates IA, IA, the document is determined to be a small size document DI by processing this detection signal. When the leading edge of the subsequent small-sized original DI passes the original passage detection sensor PS3, timing by the timer [3 starts, and when the set timing corresponding to the small-sized original D1 ends, the motor M temporarily stops. The leading edge of the document Di is stopped at the P position shown in the figure. Document transport speed v, l during this feeding time
is the conveyance speed V of the preceding document on the document table glass 101,
(e.g. V, -1200m+u/se
e, v 2 = 500mm/5ee) aNote that r! at the above temporary stop position P! Since the leading edge of the document DI is in the vicinity of the document table glass lot and is not in pressure contact with the conveyor belt 8, it is close to the trailing edge of the preceding document at a short distance.

■ Next, at the end of scanning exposure, turn on the main motor,
By turning on the conveyance 'M' and the magnetic clutch Kl, the preceding document is conveyed by the conveyor belt 8, and the document is delivered to the paper ejection roller I3.
After that, the paper is discharged and placed on the paper discharge tray 14. At the same time, the subsequent original is slid from the standby position onto the original platen glass +01, and the stopping operation causes the r! The document reaches the document stomper 102 and the document exchange is completed.

At this time, the document conveyance based on timer t4 is in high-speed conveyance mode v1.

(2) Next, FIG. 6(C) shows the process of feeding and transporting the large size original K (B4.A3) D2. When the leading edge of the subsequent large size/JNfgD2 passes the document passage detection sensor PS3, time measurement by the timer (7) is started.
When the set time corresponding to the large-sized original D2 is completed, the motor M is temporarily stopped, and the leading edge of the original DI is stopped at the Q position shown in the figure. The transport speed of yKfI4 during this feeding time t7 is vl. Furthermore, since the feeding time [7] is set smaller than the feeding time (3) for the small-sized original DI, the original stopping position Q is close to the intermediate conveyance roller 5. g The leading edge of the document D2 at the stop position and the document stopper 10 placed on the document table glass 101.
A predetermined distance is maintained from the trailing edge of the preceding document that is in contact with 2.

According to the automatic i-document conveying device according to the present invention, even if the document sizes are different, the leading edge of the subsequent document approaches the trailing edge of the preceding yK product and reaches the minimum required interval by preliminary travel. Therefore, at the same time that the preceding original is ejected toward the paper output tray, the following original is also restarted from the pause position IP or Q and is transported accordingly.The original transport distance is shortened, reducing the time for exchanging originals. Is possible. This increases the continuous copying speed (number of copies per minute).

Further, since the document conveyance speed V in the preceding forward movement distance of the subsequent document can be set independently of the conveyance speed V of the preceding document, by setting the speed v2 to a low speed, the feed roller 3 The separation by the double-feed prevention roller 4 can improve the separation performance by performing low-speed separation. Furthermore, by lowering the speed, the accuracy of the stopping position is improved.

It is clear that when feeding the first sheet, if the sheet is conveyed at low speed v2 up to sensor PS3 and then at v, the same effect will be obtained for the first sheet.

In addition, since the start of re-conveying to eject the stack from the stop position of the document stopper 102 and the double-feed prevention process at the start of document feeding are not turned on at the same time, the load on the motor is reduced and consumption is reduced. It has become possible to save power and install a low torque motor.

Furthermore, the document nip of the intermediate conveyance roller 5 and the subsequent U-turn of the document by the guide plate 6 are performed smoothly due to the document being fed at low speed, and there is little damage to the leading edge of the document.

In this example, the two drive systems described above are controlled and operated using one motor and two electromagnetic clutches, but it is also possible to perform similar operations using two motors and one electromagnetic clutch. .

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 clock starts from the passage detection of the reversed original passage detection sensor PS5, and the time is increased as described above. A similar effect can be obtained by setting a temporary stop position for each size original and small size original.

〔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 addition, it is possible to reduce the load on the motor, save power consumption, and install a small, low-torque motor.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the document conveyance path of the automatic document feeder according to the present invention, and FIG. 2 is a diagram showing the drive system of the automatic document feeder (
FIG. 3 is a perspective view showing the document conveyance system and drive system inside the apparatus, and FIG. 4 is a plan view of essential parts of the automatic document conveyance device. 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 yK#% conveyance 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 a diagram showing the document feeding process. FIG. 10 is a flowchart of the conveyance process, FIG. 10 is a time chart thereof, and FIG. 11 is a plan view showing the stationary state of documents of various sizes. l... Original table IA... Width regulation plate 1B
...Pinion gear LC...Rack gear 2...
Pickup roller 3...Feet held 3A...Feed roller 4...Double feed prevention roller 5...Intermediate conveyance roller 6...Guide plate 8...Conveyance belt 9...
- Conveyance belt drive roller 13... Paper ejection roller 14... Paper ejection tray 2
0...Motor drive shaft 21...Intermediate shaft 22...
・Feed roller shaft 23...Intermediate conveyance roller shaft 30
...Original reversing section 31.32.33...Conveying roller group 34...Guide plate 101...Image exposure section (original table glass) 102...
Original stopper 110...Control panel Ill...Copy buttons B I, B2, B3, B4, B5...
・Toothed belt P 1. P2. P3. P4. P5. P6
．． P7. P8. P9゜PIO, pH...Toothed googly Kl, 2...N, magnetic clutch (M, C) M...Servo motor D...Document Dl...Small size document (B5.A4) D2...Large size original (B4.A3)
PSI...Document size detection sensor PS2...Document set detection sensor PS3...Document passage detection sensor PS4...Document discharge detection sensor 5...Reverse gK Document passage detection sensor High-speed transport mode ■1.・Low speed transport mode

Claims (3)

[Claims] (1) Multiple sheets of originals are sequentially conveyed to the image exposure unit, the originals are stopped at the image exposure unit, the optical system is moved to perform scanning exposure, and after exposure, the originals are transported to the original output tray. In the automatic document feeder, feeding of a subsequent sheet document is started before the exposure operation of the preceding sheet document is completed,
The document is temporarily stopped at a predetermined position in front of the image exposure section and is placed on standby, and the temporary stopping position of the subsequent document is variably set based on a document size detection signal from a detection means for detecting the size of the document. An automatic document feeder featuring: (2) Set at least two subsequent document temporary stop positions according to the document size, and set the distance on the transport path between the trailing edge of the preceding document and the leading edge of the paused subsequent document so that the difference is small depending on the document size. 2. The automatic document feeder according to claim 1, wherein the temporary stop position is set so that the document feeder has the following characteristics. (3) The automatic document feeder according to claim 1 or 2, wherein the speed of the document feeding operation to feed the document to the temporary stop position is equal to or lower than the document conveyance speed above the image exposure section.