JPH06127723A - Paper sheet transporting device - Google Patents

Abstract

PURPOSE:To maintain the excellent paper separating performance even if the paper transport speed varies, when the paper sheets are transported in separation one by one. CONSTITUTION:The press contact force for a normal revolution assorting roller 55 of a reverse revolution assorting roller 56 is applied by a coil spring 84 through a supporting plate 81, supporting shaft 82, and a lever 83. The press contact force N1 for the time from the paper feed to the application of resistance by a resistor roller 58 is set to a proper pressure for separating a paper sheet for the transport speed v1 by the normal revolution assorting roller 55. After the application of resistance, the paper sheet is transported at a high speed v2 by the resistor roller 58 and since a solenoid SL is turned OFF at this time, an adjusting lever 85 regulates the lever 83, and the press-contact force for the roller 55 of the roller 56 is weakened. At this time, the press- contact force N2 is a proper pressure for separating the sheet transported at a speed v2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet conveying device, and more particularly to a sheet conveying device which separates sheets in a stacked state and sends them in one direction.

[0002]

2. Description of the Related Art In recent years, in order to improve copy efficiency, it is widely practiced to construct a copying system by combining an electrophotographic copying machine with an automatic document feeder. Further, there is a demand for speeding up the copying process, and along with the speeding up of copying paper transportation in the main body of the copying machine, there is also a demand for high speed transportation technology for paper (original) even in an automatic document feeder.

By the way, in the paper transport technology, a paper feed mechanism that reliably separates the stacked paper sheets into one and feeds them in a certain direction without skewing is extremely delicate and has a difficult problem. There is a limit to speeding up.
Therefore, a conveying means (register roller) having a paper register function is provided on the downstream side of the separating means in the conveying direction.
The original separated into sheets is brought into contact with the nip portion of the register roller to form a slight loop at the leading end to adjust the posture of the original, and then the original is conveyed at high speed.

However, when conveyance is started at high speed by the register roller, if the drive of the upstream separating means is stopped, the separating means acts as a large load for conveying the original until the original passes through the separating means. However, there has been a problem that the original is damaged or a noise (loop elimination sound) is emitted at the moment when the loop at the leading end is eliminated. As a solution to this problem, it has been proposed to rotate the separating means even when the document is conveyed at high speed by the register roller. Although this reduces the damage to the document and the loop elimination sound, the separation performance is deteriorated, and there is a possibility that the document is fed. That is, the separating means prevents the first and second originals conveyed at the separation conveyance speed (first speed) from advancing at the second and third originals that are about to be fed at the same speed. Is configured. But,
When the first original is conveyed by the register roller at the second speed higher than the first speed, the second and third originals are also fed at the second speed and rush into the separating means. To do. However, the separating performance of the separating means does not effectively act on the next document fed at the second speed, and the probability that the next document will slip through the separating means increases.

[0005]

SUMMARY OF THE INVENTION Therefore, the object of the present invention is to eliminate the damage of the paper and the noise for eliminating the loop, and the paper separation performance is not deteriorated even when the high speed conveyance is performed. It is to provide a paper transport device. In order to achieve the above object, the sheet conveying device according to the present invention,
The pick-up means for the stacked sheets, the separating means for separating the picked-up sheets into one sheet, and the conveying means for the separated sheets are sequentially arranged, and rotation driving means for them are provided to convey the sheets. And a separating member for separating the conveyed sheet into one sheet. Furthermore, between the normal rotation member and the separation member,
The first pressure required to separate the sheet when the sheet is conveyed at the first speed by the forward rotation member, and the sheet when the sheet is conveyed at the second speed by the downstream conveying unit. The pressurizing means for selectively acting the second pressure required for separation is provided. The separating means is driven by the first driving means (first speed), and at this time, the leading edge of the sheet separated into one sheet comes into contact with the transporting means which is not driven, and the leading edge portion of the sheet forms a loop. At the same time, the skew is corrected. After a certain period of time, the conveying unit is driven by the second driving unit (second speed), and when the conveying unit starts conveying the sheet, the separating unit is driven by the first driving unit for a predetermined time. The predetermined time is at least the time until the loop at the leading edge of the paper is eliminated, and the load on the paper is significantly reduced by driving the separating means, the loop elimination sound is no longer generated, and the paper is not damaged. Disappear. On the other hand, the pressurizing means applies the first pressure between the forward rotation member and the separating member until the conveying means is driven, and operates the second pressure after the conveying means is driven. Let That is, the pressure of the separating means is switched to an optimum value according to the sheet conveying speed, and the separating performance of the separating means does not deteriorate.

Usually, the second speed of the conveying means is set to be higher than the first speed of the normal rotation member, and the first pressure is such that two or more sheets are interposed between the normal rotation member and the separating member. The separation member rotates so as to push the paper back to the upstream side by the first drive means when the sheet is moved, and is set to a value that rotates following the conveyance of the sheet to the downstream side when one sheet is interposed. . At this time, the second pressure is set to be lower than the first pressure. If the pressure becomes small, even if one sheet of paper comes in between the forward rotation member and the separation member and the second and third sheets of paper rush into it, even if the separation member is driven to rotate, immediately It stops and reverses, and pushes the inrush paper back to the upstream side. When one sheet is conveyed while the second pressure contact force is applied, the separation member is driven to rotate,
Either in stop or reverse.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the paper conveying apparatus according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows an automatic document feeder 50 (hereinafter referred to as ADF), a copying machine main body 1 and a sorter 90, which is an embodiment of the present invention.

A photoconductor drum 10 is installed at a substantially central portion of the copying machine body 1 so as to be rotatable and driven in a direction of an arrow a at a constant peripheral velocity v. Around the photosensitive drum 10 along the rotation direction thereof, a main eraser 11, a charging charger 12, a sub-eraser 13, a magnetic brush type developing device 14, a transfer charger 15, a sheet separation charger 1 are provided.
6. A blade type cleaner 17 is arranged. Further, an optical system 20 is arranged above the photoconductor drum 10.

The photoconductor drum 10 is a well-known one having a photoconductor layer provided on the surface thereof, and the main eraser 11, charging charger 12, sub-eraser 13 are rotated in the direction of arrow a.
Then, the image of the original document set on the platen glass 29 is exposed by the optical system 20. The electrostatic latent image formed on the photosensitive drum 10 by exposure is converted into a toner image by the developing device 14.

The optical system 20 scans an image of a document set on the platen glass 29 onto the photosensitive drum 10 directly below the platen glass 29. That is, at the time of image scanning, the exposure lamp 21 and the first mirror 22 are integrated into the peripheral velocity v of the photosensitive drum 10 (constant regardless of equal magnification or variable magnification) with respect to v / m (m: copy magnification). ) Speed with arrow b
Move in the direction. At the same time, the second mirror 23 and the third mirror 24 move in the direction of arrow b at a speed of v / 2m. When the copy magnification is changed, the projection lens 25 moves on the optical axis and the fourth mirror 26 swings to correct the optical path length.

Copy sheets are accommodated in the upper sheet feeding section 31 and the lower sheet feeding section 34, and are fed one by one from any one of them according to the operator's selection. Each paper feed unit 31, 3
4, paper feed rollers 32 and 35 and separation rollers 33 and 36 including a forward rotation roller and a reverse rotation roller are installed.
The sheet fed from the upper sheet feeding section 31 is conveyed by the transport roller 37.
It is sent out to the timing roller 38 installed immediately before the image transfer section through b and 37c. The sheets fed from the lower sheet feeding section 34 are conveyed by rollers 37a, 37b, 37c.
Through the timing roller 38.

Further, just above the upper sheet feeding section 31, there is a double-sided /
An intermediate tray 47 is provided for processing the synthetic copy. The sheet re-fed from the intermediate tray 47 by the sheet re-feeding roller 48 and the sheet separated by the separating roller 49 is sent out to the timing roller 38 through the conveying roller 37c. The sheet fed to the timing roller 38 once stands by here, and is fed to the transfer section by turning on the timing roller 38 in synchronization with the image formed on the photosensitive drum 10. The paper comes into close contact with the photoconductor drum 10 at the transfer portion, and the transfer charger 15
The toner image is transferred by the corona discharge from the photosensitive drum 10 by the AC corona discharge from the separation charger 16 and the stiffness of the paper itself. After that, the paper is sent to the fixing device 40 through the conveyor belt 39,
After the toner is fixed, the toner is accommodated in the sorter 90 through the transport rollers 41 and 42.

On the other hand, the photoconductor drum 10 has an arrow a after the transfer.
The cleaner 17 removes the residual toner, and the main eraser 11 erases the residual charge to prepare for the next copying process. In the composite copy mode, the paper to which the images of the odd-numbered originals have been transferred is changed in the paper-passing direction downward by the paper-passing switching claw 43, and the transport roller 4
It is accommodated on the intermediate tray 47 through 4, 45 and 46. In double-sided copy mode, the paper is temporarily sorted by 90
The sheet is conveyed to the entrance portion of the sheet, and is switched back by reversing the conveying roller 42, and the sheet passing direction is changed downward by the switching claw 43.
It is accommodated on the intermediate tray 47 through 5,46. After that, the paper is re-fed from the intermediate tray 47 for double-sided / composite copying of the image of the even-numbered original.

By the way, in the copying machine main body 1, the copying process is started, and the first sheet is the timing roller 3.
When waiting immediately before 8, the first-out processing is performed in which not only the second sheet but also the third sheet is preliminarily fed to the feed path. For example, in the paper feeding from the lower sheet 34, second sheet P ₂ Following first sheet P ₁ is fed to the feeding path, further the third sheet P ₃ Conveyor roller 3
Paper is fed until just before 7a. Such a first-out process is performed not only in the multi-copy mode but also in the single-copy mode using the ADF 50 to improve the copy speed.

On the other hand, the sorter 90 is a non-sort tray 9
This is a well-known one having a 1- and 20-stage sort tray 92, and a description thereof will be omitted. Next, the ADF 50 will be described in detail. FIG. 2 shows a schematic configuration of the ADF 50. This AD
F50 is roughly the document tray 51, the pickup roller 54, the register roller 58, the conveyance belt 60, and the reverse /
It is composed of a discharge roller 65 and a discharge tray 69.
The ADF 50 is installed on the upper surface of the copying machine main body 1 so that the conveyor belt 60 is located on the platen glass 29, and the operator manually sets the document. Therefore, the hinge fitting (not shown) provided on the back side is provided. ), The platen glass 29 can be opened. The opening / closing of the ADF 50 is detected by a magnet sensor (not shown), and the operation of the ADF 50 can be performed only when the sensor detects that the ADF 50 is properly closed.

The document tray 51 is a pair of side regulating plates 5.
2. The tip stopper 53 is provided. The original document is placed on the tray 51 with the first page facing upward. The leading end stopper 53 swings downward during paper feeding and retracts from the regulation position. The pickup roller 54 is attached to the tip of a lever 57 that is rotatable about a support shaft of the forward rotation separating roller 55 as a fulcrum, and moves down together with the lever 57 to press the upper surface of the document when feeding. The reverse separating roller 56 is elastically pressed against the forward separating roller 55 from below.
This pressure contact force can be switched in two steps by the electromagnetic solenoid SL (see FIGS. 3 and 4) in order to improve the document separation performance, and its configuration will be described in detail below.

The register roller 58 is provided with pinch rollers 59a and 59b on the upper and lower sides thereof, and temporarily positions the leading end of the fed document at the nip portion with the pinch roller 59a.
Thereafter, the original is reversed and conveyed to the entrance of the platen glass 29. The conveyor belt 60 is a platen glass 29.
Driven roller 61 and drive roller 62 so as to cover the entire surface of
It is stretched endlessly between and. In order to bring the surface of the belt 60 into contact with the platen glass 29 at a constant pressure inside the conveyor belt 60, a large number of backup rollers 63 are rotatably installed. This conveyor belt 60
Is normally rotated in the direction of arrow c, and the original
The tip is aligned with the exposure reference point O, which is the boundary between the platen glass 29 and the platen glass 29, and stopped. The document feeding / conveying / stopping / discharging process will be described in detail below.

As a method of stopping the original at the exposure reference point O, there are a scale mode and a pulse control mode. The scale mode is a mode in which the leading end of the scale 28 is projected from the surface of the platen glass 29, and the leading end of the original document conveyed by the conveyance belt 60 is brought into contact with the scale 28 and forcibly stopped. In the pulse control mode, the scale 28 is retracted below the surface of the platen glass 29, the amount of document transportation is counted based on the number of rotations of the drive motor, and the document is transported so that the leading end thereof reaches the exposure reference point O. In this mode, the rotation of the belt 60 is stopped.
The ADF 50 adopts the pulse control mode.

The reversing / discharging roller 65 is provided with pinch rollers 66a and 66b at the upper and lower sides thereof, and further with a switching claw 67 for the purpose of switching the sheet passing path for reversing the double-sided original around the reversing / discharging roller 65. There is. That is, when the document is reversed, the switching claw 67 is located away from the surface of the roller 65 as shown in FIG.
The document discharged from above is guided to the outer peripheral surface of the roller 65. The document is inverted around the roller 65 and returned to the platen glass 29 again. At this time, the conveyor belt 60 is rotationally driven in the direction opposite to the arrow c. On the other hand, when the document is discharged, the tip of the switching claw 67 is the reverse / discharge roller 65.
The original is ejected onto the tray 69 through the ejection roller 68 while being guided by the lower surface of the switching claw 67.

The ADF 50 is driven and controlled by various motors, clutches, and sensors shown in FIGS. That is, the pickup roller 54 moves up and down by a cam (not shown) driven to rotate by the pickup motor M1, and the lowered position is detected by the pickup sensor SE10 which is turned on and off by the notch of the cam. As shown in FIG. 15, the pickup roller 54 and the separation rollers 55 and 56 are rotationally driven by the paper feeding motor M2, and the conveyor belt 60 is driven by the main motor M3 that can rotate in the forward and reverse directions. A one-way clutch OCL1 is provided between the paper feeding motor M2 and the forward rotation separating roller 55.
, And a torque limiter TL is interposed between the reverse rotation separating roller 56. The reversing / discharging roller 65 and the discharging roller 68 are rotationally driven by the reversing / discharging motor M4. The register roller 58 is rotationally driven by the paper feeding motor M2 by turning on the electromagnetic clutch CL at the time of feeding the document, and is turned off by the main motor M3 when the document is transported by the transport belt 60. A one-way clutch OCL2 is interposed between the main motor M3 and the register roller 58 so that the register roller 58 is rotated only when the motor M3 rotates in the normal direction and the rotational force is not transmitted when the motor M3 rotates in the reverse direction. An electromagnetic brake BRK1 is attached to the support shaft of the register roller 58, and an electromagnetic brake BRK2 is attached to the support shaft of the drive roller 62 of the conveyor belt 60 to prevent unnecessary rotation of the register roller 58 and the conveyor belt 60. It is like this.

Further, in order to detect the number of revolutions of each of the motors M2 and M3, encoders E2 and E3 for generating a rotation pulse signal are attached, and the pulse signal is inputted to the microcomputer CPU2. The pulse signal is used for detecting the document length and controlling the document stop position. Further, the following document detection sensor is installed in the ADF 50. The empty sensor SE11 is installed in the vicinity of the pickup roller 54 and detects the presence or absence of a document on the tray 51. The register sensor SE12 is installed immediately in front of the register roller 58 and detects the document sent from the tray 51. The width sensor SE13 is installed on the side portion at substantially the same position as the sensor SE12, and has a role of detecting the size of the document in the width direction. The timing sensor SE14 is installed at the entrance of the platen glass 29,
It serves as a reference for document conveyance control and has the role of detecting the length of the document. The discharge sensor SE15 detects the document discharged from the platen glass 29, and the sensor SE1
Reference numeral 6 detects the document that has been inverted by the inversion / discharge roller 65.

Here, the judgment mechanism will be described. As shown in FIG. 3, the document D is fed to the left. The rotation direction for conveying the document is x, and the rotation direction for pushing back the document is y. The pickup roller 54 is rotationally driven in the x direction at a peripheral speed v ₁ . Forward rotation separating roller 55 is x
Is driven to rotate at a peripheral velocity v ₁ . The reverse rotation separating roller 56 is rotationally driven in the y direction. Register roller 58
Is rotationally driven in the x direction at a peripheral velocity v ₂ (v ₂ > v ₁ ), and the pinch roller 59a is driven to rotate in the x direction accordingly.

The frictional force between the originals is μ ₀ , the frictional force between the paper and the normal rotation separating roller 55 is μ ₁ , and the paper and the reverse rotation separating roller 5 are
When the frictional force between 6 is μ ₂ , μ ₁ > μ ₂ > μ ₀ is set. Therefore, when a plurality of originals are interposed between the rollers 55 and 56, the uppermost original is conveyed to the downstream side at a speed v ₁ by the rotation of the forward rotation separating roller 55 in the x direction.
The originals after the first sheet are pushed back to the upstream side by the rotation of the reverse separating roller 56 in the y direction.

As shown in FIG. 5, the forward rotation separating roller 55
Is attached to a spindle 71 via a holder 72, and is rotationally driven in the x direction at a peripheral speed v ₁ by a paper feeding motor M2. A one-way clutch OCL1 is interposed between the roller 55 and the motor M2. When a document is conveyed by the register roller 58 at a high speed v ₂ , the one-way clutch OCL1 allows the forward separation roller 55 to rotate at the speed V _{2 as the} document is conveyed.

The reverse separating roller 56 is provided with a holder 74.
The holder 74 is attached to the support shaft 73 so as to be rotatable in both the x and y directions. A drive holder 75 is fixed to the support shaft 73 adjacent to the holder 74 with screws 76. Bosses 74a of holders 74, 75,
A coil spring that functions as a torque limiter TL is wound around 75a in a crimped state. One end of the torque limiter TL is locked to the driving holder 75, and when the holder 75 rotates together with the support shaft 73 in the y direction, the torque limiter TL is included.
Is wound in a direction in which the boss portion 74a of the holder 74 is tightened. The reverse rotation separating roller 56 is rotationally driven in the y direction by the torque Ts at this time. By the way, when the reverse rotation separating roller 56 is in direct contact with the forward rotating separation roller 55 or when it is in contact with one original and receives the force in the x direction at the speed v ₁ or v ₂ , the torque received at this time is the torque. If the torque is set to be larger than the torque Ts of the limiter TL, the reverse separation roller 56 is driven to rotate in the x direction.
However, when the second and third originals enter between the rollers 55 and 56, the torque received by the reverse rotation separating roller 56 is T.
It becomes smaller than s, the roller 56 switches to rotation in the y direction, separates the second and third originals, and pushes them back to the upstream side.

Next, the pressure contact force between the separating rollers 55 and 56 and its imparting function will be described. In the present embodiment, the pressure contact force N ₂ when the document is conveyed by the register roller 58 at the speed v ₂ is opposed to the pressure contact force N ₁ when the document is conveyed by the forward rotation separating roller 55 at the speed v _1. Is set small. This is because the separation performance at the speed v ₂ is not deteriorated as described in detail below.

FIG. 3 shows a state where the pressure contact force is large N ₁ , and FIG. 4 shows a state where the pressure contact force is small N ₂ . More specifically, the reverse separation roller 56 is supported by the support plate 81,
The base portion of No. 1 is integrally connected to a lever 83 via a rotatable support shaft 82. A coil spring 84 is fixed to the upper end of the lever 83, and biases the lever 83 counterclockwise with a spring force Pa. On the other hand, an adjustment lever 85 is rotatably attached to the support shaft 82. Adjustment lever 85
Has its lower end locked to the plunger 87 of the electromagnetic solenoid SL, and its upper end is close to the side of the lever 83, and the coil spring 86 is fixedly attached. The coil spring 86 urges the adjusting lever 85 clockwise with the spring force Pb.

In such a structure, when the electromagnetic solenoid SL is turned on (see FIG. 3), the plunger 87 is retracted, and the adjusting lever 85 causes the spring force P of the coil spring 86.
It slightly rotates counterclockwise around the support shaft 82 as a fulcrum against b. At that time, the upper end projection 85a of the adjusting lever 85
Is located away from the side portion of the lever 83, and the lever 83 receives the spring force Pa of the coil spring 84, and the reverse rotation separating roller 56 applies a force of N _{1 to} the forward rotating separation roller 55 based on this spring force Pa. Pressure contact. On the other hand, the electromagnetic solenoid SL
Is off (see FIG. 4), the plunger 87 projects and the adjusting lever 85 causes the spring force Pb of the coil spring 86 to rise.
Rotates in the clockwise direction with the support shaft 82 as the fulcrum. The spring force Pb is set to be larger than Pa, the upper end projection 85a of the adjusting lever 85 presses the side portion of the lever 83, and the lever 83 is pressed by the spring force of Pc (Pb-Pa).
Will rotate slightly clockwise. Lever 83
Clockwise rotation weakens the pressure contact force of the reverse rotation separation roller 56 against the forward rotation separation roller 55, and the pressure contact force N _{2 at} this time is smaller than the pressure contact force N ₁ when the electromagnetic solenoid SL is turned on. .

Here, the document feeding operation will be described.
When the document D is placed on the tray 51 and a copy start signal is issued, the pickup roller 54 descends and holds the document D. Next, the paper feed motor M2 is turned on, the pickup roller 54 and the forward rotation separating roller 55 are rotationally driven in the x direction, and the reverse rotation separating roller 56 is rotationally driven in the y direction. At the same time, the electromagnetic solenoid SL is turned on,
The adjustment lever 85 releases the restriction on the lever 83, and the lever 83 receives the spring force Pa of the coil spring 84, so that the reverse rotation separation roller 56 is rotated in the forward direction.
It is pressed against 5 with a pressure of N ₁ .

The reverse separating roller 56 is composed of rollers 55, 5
When the original is not fed in between 6 and x at the peripheral speed v ₁ .
Since the driving force received from the forward rotation separating roller 55 rotating in the direction is larger than the torque Ts of the torque limiter TL, the rotation is driven in the x direction. When one document is fed between the rollers 55 and 56 by the pickup roller 54, the document is fed by the forward rotation separating roller 55 at a speed v ₁
Is transported to the downstream side. At this time, the reverse rotation separating roller 5
6 receives a driving force in the x direction via a single original, and the driving force at this time is larger than the torque Ts of the torque limiter TL and maintains the driven rotation in the x direction. However, when the second and third originals are fed between the rollers 55 and 56, the driving force in the x direction received by the reverse separating roller 56 via the plurality of originals is smaller than the torque Ts, The reverse rotation separating roller 56 immediately switches to rotation in the y direction. By this rotation, the second and third originals are pushed back to the upstream side, and only the uppermost (first) original is securely separated and sent to the nip portion between the register roller 58 and the pinch roller 59a. To go.

At this time, the register roller 58 is locked by turning off the electromagnetic clutch CL so that the driving force from the sheet feeding motor M2 is not transmitted and turning on the electromagnetic brake BRK1. The leading edge of the original separated into one sheet is the register roller 58 and the pinch roller 5.
It abuts the nip portion with 9a, and a loop is formed at the tip portion (see FIG. 4). The leading edge of the document is the register sensor SE
The paper feed motor M2 is once turned off for a certain period of time counted by the timer T102 after being detected by 12. Timer T
102 is set to be slightly longer than the time during which the document is conveyed at the speed v ₁ for the distance L (see FIG. 3) from the detection point of the sensor SE12 to the nip portion of the rollers 58 and 59a.
Within this time, the leading edge of the document forms a loop, and skew feeding is corrected.

Next, the electromagnetic brake BRK1 for the register roller 58 is turned off and the paper feeding motor M2 is turned on. With this, the register roller 58 moves the peripheral speed v.
₂ (value larger than v ₁ ) is rotationally driven in the x direction, and the pickup roller 54 and the separating rollers 55 and 56 are also restarted to be rotationally driven. Simultaneously with turning on of the sheet feeding motor M2 here, the electromagnetic solenoid SL is turned off, the lever 83 is regulated by the adjusting lever 85, and the reverse rotation separating roller 5
The pressure contact force of No. 6 with respect to the forward rotation separating roller 55 is weakened to N ₂ (see FIG. 4).

In this state, the first original document D ₁ registered in the nip portion between the rollers 58 and 59a is conveyed at a speed v ₂ by the rotation of the register roller 58. At this time, the pickup roller 54 moves upward to release the pressure on the document. The forward separating roller 55 is the document D ₁
Is applied with a driving force in the x direction at a speed v ₂ faster than its own speed v _1, and is driven and rotated at the speed v ₂ by the action of the one-way clutch OCL1. The reverse separating roller 56 is also given a driving force in the x direction at a speed v ₂ from the document D ₁ . Due to the relationship between the driving force and the torque Ts of the torque limiter TL at this time, the reverse rotation separating roller 56 is driven to rotate in the x direction, stopped, or reversely rotates in the y direction.

However, since the pressure contact force N ₂ is set smaller than N ₁ , the driving force received from the document D ₁ is not so large. Therefore, even if the second document D ₂ is moved between the rollers 55 and 56 by the document D ₁ ,
The driving force received from the _second document D ₂ is smaller than the torque Ts, and even if the reverse rotation separating roller 56 is driven to rotate in the x direction, it is immediately switched to the reverse rotation in the y direction and pushes the document D ₂ back to the upstream side. . Even if the document D ₁ is conveyed at the speed v ₂ , if the large pressure contact force N ₁ is applied, the reverse rotation of the reverse rotation separating roller 56 is delayed in the reverse rotation, and the document D ₁ is delayed during this response delay. There is a possibility that the tip portion of ₂ may pass between the rollers 55 and 56 (separation performance deteriorates). Further, the third document D ₃ is the rollers 55, 5
When it comes in between 6, the reverse separating roller 56 causes the document D
While pushing back ₃ , the second original D ₂ is further conveyed, and the original D ₂ is conveyed to the downstream side by the register roller 58 together with the _first original D ₁ . The above is one example in which the forwarding is generated. This kind of transportation is
Due to the demand for high-speed document transportation, the register roller 5
This is remarkable when the conveyance speed v ₂ by 8 is set to be higher than the conveyance speed v ₁ by the forward separating roller 55. In this embodiment, by weakening the pressure contact force from N ₁ to N ₂ ,
The reverse separation roller 56 is prevented from lowering the separation performance.

Further, in this embodiment, when restarting the conveyance of the separated original by the register roller 58, the separating rollers 55 and 56 are driven simultaneously with the driving of the register roller 58.
Also drives. If the separating rollers 55 and 56 are stopped when the conveyance is restarted, the loop formed at the leading end of the document is canceled at once by the conveying force at the speed v ₂ , and a large loop eliminating sound is generated or the image surface of the document is displayed. May cause damage. However, by driving the sorting rollers 55 and 56 at the same time as driving the register roller 58, not only the feeding can be prevented, but also the loop is gently eliminated, and the loop elimination sound and the document damage are almost eliminated. The time for rotating the separating rollers 55, 56 after the restart of the conveyance may be set to at least the time for eliminating the loop at the leading end of the document. However, considering the carry-forward prevention function, it is desirable to set it longer than the loop elimination time.

Next, the relationship between the pressure contact force of the separating rollers 55 and 56 and the torque of the torque limiter TL will be described in detail. As shown in FIG. 6, the frictional force between the paper sheets is μ ₀ , the frictional force between the paper sheet and the forward separating roller 55 is μ ₁ , the frictional force between the paper sheet and the reverse separating roller 56 is μ ₂ , and the roller between the rollers 55 and 56. Friction force is μ ₃ , and pressure contact force between rollers 55 and 56 is N
(G), the torque of the torque limiter TL is Ts (g-c
m), the radius of the forward rotation separating roller 55 is R ₁ (cm), and the radius of the reverse rotation separating roller 56 is R ₂ (cm).

The forces acting on the reverse rotation separating roller 56 are the following two. Fa: Forced reverse rotation driving force from the spindle 73 Fb: Forward rotation driving force from the forward rotation separating roller 55 The forward rotation driving force Fb is as shown by (A), (B) and (C) in FIG. A) Fb ₁ : When paper does not exist between rollers (B) Fb ₂ : When one paper exists between rollers (C) Fb ₃ : When two or more papers exist between rollers The normal rotation driving force Fb changes depending on the above three conditions and the type of paper. On the other hand, the reverse rotation forced driving force Fa is always constant if the reverse rotation torque Ts is constant.

Therefore, the following equation holds. (A) Fb ₁ = μ ₃ N (1) (B) Fb ₂ = μ ₂ N (2) (C) Fb ₃ = μ ₀ N (3) From the forward rotation sorting roller 55 to the reverse rotation sorting roller 56 The forward rotation torque Tf (g-cm) applied is (A) Tf ₁ = Fb ₁ R ₂ = μ ₃ NR ₂ (4) (B) Tf ₂ = Fb ₂ R ₂ = μ ₂ NR ₂ ( 5) (C) Tf ₃ = Fb ₃ R ₂ = μ ₀ NR ₂ (6) On the other hand, the reverse rotation torque Ts is constant in any of (A), (B) and (C).

Ts: const (7) That is, the reverse rotation separating roller 56 rotates reversely when Ts> Tf and rotates normally when Ts <Tf. However, in reality, the inertia torque Tα and the friction loss Tβ of the reverse rotation separating roller 56 are generated, so that the roller 56 is Ts> Tf + Tα + Tβ: reverse rotation Ts <Tf + Tα + Tβ: normal rotation. The friction loss Tβ is substantially constant, but the inertia torque Tα is proportional to the sheet transport speed v.

Here, the conditions for surely separating the sheet and giving a sufficient conveying force will be considered. (A) When no paper intervenes When no paper intervenes, as shown in FIG. 6A, the rollers 55 and 56 are in direct contact with each other, and at this time, the reverse separating roller 56 needs to rotate normally. Is the following equation (8)
It is represented by.

Μ ₃ N> Ts / R ₂ (8) At this time, when the reverse rotation separating roller 56 rotates in the reverse direction, the frictional force between the rollers 55 and 56 increases and the service life becomes short. Further, when the sheet plunges between the rollers 55 and 56, there is a possibility that the sheet may be caught by the reverse rotation separating roller 56. Therefore, it is required to satisfy the equation (8). (B) When one sheet intervenes As shown in FIG. 6B, when one sheet intervenes between the rollers 55 and 56, the reverse rotation separating roller 56 can be rotated forward or backward. Well, the conditions are as follows. (B ₁ ) Reverse rotation of the separation roller Ts> Tf + Tα + Tβ ∴Ts / R ₂ > μ ₂ N + Tα + Tβ Under these conditions, the conveyance force Ff acting on the sheet D ₁ shown in FIG. 7 is Ff = μ ₁ N (9) ) The separating force Fr acting on the paper D ₁ is Fr = μ ₂ N (10) Therefore, the condition for reliably transporting the paper D ₁ based on the equations (9) and (10) is as follows: Represented. In addition,
Fmin is the minimum required conveying force.

F = Ff-Fr = (μ ₁ −μ ₂ ) N> Fmin (11) (B ₂ ) When the reverse-rotating separation roller is normally rotated Ts <Tf + Tα + Tβ ∴Ts / R ₂ <μ ₂ N + Tα + Tβ Under these conditions In FIG. 8, the conveying force Ff acting on the sheet D ₁ shown in FIG. 8 is Ff = μ ₁ N (9) The separating force Fr acting on the sheet D ₁ is Fr = Ts / R ₂ (12) ), (12), the condition for reliably transporting the sheet D ₁ is expressed by the following equation (13).

F = Ff-Fr = μ ₁ N-Ts / R ₂ > Fmin (13) (C) When two sheets of paper intervene As shown in FIG. 6C, between rollers 55 and 56. When two sheets are interposed, the reverse rotation separating roller 56 needs to be reverse rotation or stopped, and the conditions are as follows.

According to the equation (6), the forward rotation torque Tf ₃ applied from the forward rotation separation roller 55 to the reverse rotation separation roller 56 is μ ₀ NR ₂ . Therefore, the carrying force Ff acting on the _first sheet D ₁ shown in FIG. 9 is Ff = μ ₁ N−μ ₀ N (14) The separating force Fr acting on the _second sheet D ₂ is (C ₁ ) Reverse rotation separating roller reverse rotation Fr = μ ₂ N−μ ₀ N (15) (C ₂ ) Reverse rotation separating roller stop Fr = Ts / R ₂ −μ ₀ N (16) From the formula (14), Ff = Μ ₁ N−μ ₀ N> Fmin ∴N> Fmin / (μ ₁ −μ ₀ ) ... (17) where μ ₁ −μ ₀ > 0 From the formula (15), Fr = μ ₂ N−μ ₀ N> Frmin ∴N> Frmin / (μ ₁ −μ ₀ ) ... (18) where μ ₁ −μ ₀ > 0 From the equation (16), Ts / R ₂ −μ ₀ N> 0 ∴N <Ts / R ₂ μ ₀ (19) Here, if the conditions for surely separating and conveying the paper are summarized, the press contact force N may satisfy the following formula.

N> Ts / R ₂ μ ₃ (8 ′) N> Fmin / (μ ₁ −μ ₂ ) (11 ′) N> (Fmin + Ts / R ₂ ) / μ ₁ (13 ′) N> Fmin / (μ ₁ −μ ₀ ) ... (17) N> Frmin / (μ ₂ −μ ₀ ) ... (18) ) N> Ts / R ₂ μ ₀ (19) Here, the graph of the relationship between the pressure contact force N and the torque Ts is as shown in FIG. 10. Pressure contact force N and torque Ts
If and are set in the hatched area in FIG.
It does not cause misfeeds or misfeeds. In this embodiment, the following numerical values are set.

Μ ₀ : 0.5 μ ₁ : 2.0 μ ₂ : 1.0 μ ₃ : 5.0 R ₁ , R ₂ : 1.0 cm Fmin: 150 g Frmin: 100 g By the way, in such a separating mechanism, As described above, the torque Ts of the torque limiter TL decreases due to the inertia torque Tα of the reverse separating roller 56 and the friction loss Tβ. In particular, the inertia torque Tα depends on the transport speed.
Tα at the transport speed v ₁ by the forward separating roller 55 is T
α ₁ , Tα when the transport speed by the register roller 58 is v ₂
Is expressed as Tα ₂ , the above equations (8 ′), (13 ′), (1
9) can be rewritten as follows.

N> (Ts−Tα−Tβ) / R ₂ μ ₃ (8 ″) N> {Fmin + (Ts−Tα−Tβ) / R ₂ } / μ ₁ (13 ″) N> (Ts−) in _{Tα-Tβ) / R 2 μ} 0 ... (19 ') present _{example, Tα 1: 150g-cm Tα} 2: 50g-cm Tβ: a 50 g-cm, 10 based on this number
The graph shown in FIG. 11 is obtained by modifying the graph in FIG. In the graph of FIG. 11, diagonal hatching indicates a proper area at the transport speed v ₁ , and vertical hatching indicates a proper area at the transport speed v ₂ .

In the embodiment, in order to reduce the stress on the original as much as possible at the time of conveyance / separation (conveyance speed v ₁ ),
The torque Ts is set to 400 g-cm and the pressure contact force N ₁ is set to 450 g. Further, the pressure contact force N ₂ at the time of conveyance after the registration (conveyance speed v ₂ ) is set to 250 g. That is, when the document conveying speed between the rollers 55 and 56 becomes high and the feeding is likely to occur, the roller 5
The pressure contact force between 5 and 56 is reduced to prevent the separation performance from deteriorating.

Next, the document feeding / conveying / discharging process by the ADF 50 will be described in detail. The originals are placed on the tray 51 with the first page facing up, and the side regulating plates 5 are on both sides.
2 and the tip is regulated by the stopper 53.
The document is detected by the empty sensor SE11, and the copy process (document feeding operation) is enabled. When the print key is turned on by the operator, the pickup motor M1 is turned on for a certain period of time, and the pickup roller 54
Is lowered onto the document D ₁ and the stopper 53 is retracted [see FIG. 12 (a)]. At the same time, the electromagnetic solenoid SL is turned on to turn the reverse rotation separating roller 56 into the forward rotation separating roller 5
5 is brought into pressure contact with the first pressure contact force N ₁ .

After a fixed time, the paper feed motor M2 is turned on,
By rotating the rollers 54, 55, 56,
The first original D ₁ is separated into one and the rollers 55 and 56 are separated.
It is sent out from between and its tip comes into contact with the nip portion between the register roller 58 and the pinch roller 59a. The document transport speed at this time is v ₁ . When the leading edge of the document D ₁ is detected by the register sensor SE12, the electromagnetic brake BRK1 is turned on and the register roller 58 is locked. This is to prevent the register roller 58 from being driven and rotated by the contact of the leading end of the document D ₁ .

After a certain period of time from the detection of the leading edge of the document by the sensor SE12, if the leading edge of the document D ₁ forms a slight loop immediately before the register roller 58 [FIG. 12 (b)].
Reference], the paper feed motor M2 is turned off. As a result, the skew feeding of the document D ₁ is corrected. In addition, the pickup motor M
1 is turned on for a certain period of time, and the pickup roller 54 moves up. At the same time, the electromagnetic solenoid SL is turned off, and the pressure contact force between the rollers 55 and 56 is reduced to N ₂ .

Next, the electromagnetic clutch CL is turned on, the electromagnetic brake BRK1 is turned off, and the sheet feeding motor M2 is turned on. Thus, the document D ₁ is started to be conveyed by the register roller 58 at the speed v ₂ , and at the same time, the separating rollers 55 and 56 are also rotationally driven. Separation rollers 55, 5
As described above, the rotation of 6 eliminates the generation of the loop elimination sound and the damage of the document. Further, as described above, at this time, the pressure contact force between the rollers 55 and 56 is reduced to N ₂ to prevent the separation performance for the next originals D ₂ and D ₃ from being lowered.

At the same time that the paper feed motor M2 is turned on, counting of the number of rotation pulses of the motor M2 emitted from the encoder E2 is started, and when the n1 pulses are counted, the paper feed motor M2 is turned off and the electromagnetic brake BRK
1 is turned on and the register roller 58 is stopped. Then, the electromagnetic brake BRK1 and the electromagnetic clutch CL are turned off. This completes the advance feeding of the _first document D ₁ [see FIG. 12 (c)], and the front end of the document D ₁ is the entrance of the platen glass 29. It waits in a state of being positioned immediately before (first-out reference point P).

When the _first- out paper feeding for the document D ₁ is completed as described above, the main motor M3 is turned on normally.
At this time, the electromagnetic clutch CL is turned off, the register roller 58 is rotationally driven together with the transport belt 60,
The document D ₁ is carried on the platen glass 29 [FIG.
See (d)]. Timing sensor SE1
4 detects the leading edge of the document D ₁ , and at the same time the encoder E
3 starts counting the number of rotation pulses of the main motor M3. Then, the sensor SE14 causes the document D ₁
Upon detection of the trailing end, the pickup motor M1 is turned on a predetermined time, to press the document D ₂ pickup roller 54 is lowered for the next feed process, waits.

By the way, in the present embodiment, when the original is carried in from the first-out paper feeding position onto the platen glass 29, the register roller 58 and the conveyor belt 60 are rotationally driven by the main motor M3. This is because if both motors are driven by different motors, it is difficult to synchronize the drive start timing and the document transport speed of both motors, and special control is required for synchronization. If the two drive sources are the same, such difficulty of synchronization is eliminated.

The number of pulses from the encoder E2 and the timing sensor S which are counted while the document is being fed in advance.
The length of the document in the conveyance direction is detected by the sum of the number of pulses from the encoder E3 counted until E14 is turned off (document rear end detection). Further, the width of the document is detected by turning on and off the width sensor SE13, and the size of the document is determined by both of them. The platen glass 29 has an area corresponding to A3 size. Therefore, when the one-sided original is set on the tray 51 and the length of the original is 216 mm or less, the original is stopped when its leading end reaches the intermediate reference point O ′ [see FIG. 12 (d)],
The pre-step mode described below is executed. on the other hand,
If the length of the document exceeds 216 mm, the document is conveyed until the leading end of the document reaches the exposure reference point O, and the normal single-sided normal mode is executed.

In the pre-step mode, in order to stop the document at the pre-step position, the main motor M3 is turned off and the electromagnetic brake BRK2 is turned on when the n3 pulses from the encoder E3 are counted, and the conveyor belt is turned on. Stop 60. In this way, the conveyor belt 60
Is stopped, the leading edge of the document D ₁ is designed to reach the intermediate reference point O ′.

Next, the second document D ₂ on the tray 51 is fed to the first feed position (see FIG. 13E). The first-out paper feeding process is basically the same as that described above, and the document D ₂
N is turned on after the paper feed motor M2 is turned on after the registration
The paper feed motor M2 is turned off when one pulse is counted. As a result, the next document D ₂ stops at the first-out paper feeding position.

Next, the document D ₁ is conveyed from the pre-step position to the exposure position where the leading end of the document D ₁ is located at the exposure reference point O.
First, the main motor M3 is turned on. Now, the original D
The conveyance of ₁ and D ₂ is restarted, and at the same time when the motor M3 is turned on, the counting of the number of pulses from the encoder E3 is started. In the present embodiment, the leading edge of the document is set to reach the exposure reference point O from the intermediate reference point O ′ at the time when the pulse from the encoder E3 is counted by n5 after the main motor M3 is turned on. Therefore, the main motor M3 is turned off, the electromagnetic brake BRK2 is turned on, and the conveyance belt 60 is stopped at the time when the pulse from the encoder E3 is counted n5 pulses. Thus, the document D ₁ is stopped at the exposure position where the leading end of the document D ₁ is located at the exposure reference point O. Two
The leading edge of the first document D ₂ reaches the intermediate reference point O ′ and stops [see FIG. 13 (f)].

On the other hand, at the same time as the conveyance of the originals D ₁ and D ₂ is started (the main motor M3 is turned on), the pickup motor M1 is turned on to start the lowering of the pickup roller 54 from the upper home position to move the pickup roller 54. It is pressed against the _third document D ₃ . As described above, the pressing of the _second document D ₂ is started after the rear end of the _first document D ₁ is detected by the register sensor SE12.
By the way, when the third document D ₃ is fed in advance, the size of the _first document D ₁ has already been detected, and the size of 216 m
It has been found to be less than or equal to m. Then, the second document D ₂ is also considered to have the same size. In the present ADF 50, if the document length is 216 mm or less, even if the pickup roller 54 starts descending at the same time when the main motor M3 is turned on, if the document is 216 mm or less before the pickup roller 54 is completely lowered. Even if the rear end does not pass through the detection point of the register sensor SE12, it is designed so as to pass through the pressing point of the pickup roller 54. The descent of the pickup roller 54 is started early, and at the same time, the paper feed motor M2 is turned on to turn the rollers 54, 5 on.
By rotating 5 and 56, the document feeding process can be started early. In this case, it goes without saying that the pickup roller 54 does not press the rear end portion of the document D ₂ and the feeding of the document D ₃ is not hindered. Incidentally, even the timing for starting the descent of the pickup roller 54 is not previously conveyed simultaneously with the start of the document D _1, D _2, the rear end detection timing of the document D ₂ of the above in the register sensor SE12 which has been conventionally performed If done earlier, the document feeding process will be accelerated accordingly.

By the way, in the present ADF 50, n5 pulses from the encoder E3 are counted, and the document D ₁
The tip of reaches the exposure reference point O, the leading end of the original D ₂ reaches the intermediate reference point O ', at the time when the main motor M3 is turned on, third original D ₃ is the tip is still registers It has not reached the nip portion between the roller 58 and the pinch roller 59a, but reached the nip portion with a slight delay,
Wait once [see FIG. 13 (f)]. Here, the image exposure by the optical system 20 is performed on the _first document D ₁ . During this image exposure, the paper feed motor M2 is turned on to feed the _third document D ₃ in advance (see FIG. 13 (g)).
This pre-feeding process is completed before the image exposure of the _first document D ₁ is completed. Therefore, when a single-sided copy is performed on a single-sided document using the ADF with a copy number of 1, This is an indispensable condition in order not to reduce the copy speed. In order to achieve this condition, it is necessary to increase the paper feed speed or advance the paper feed start timing. However, if the sheet feeding speed is increased, the damage of the document becomes large, the sheet is skewed, and the separation performance of the reverse separation roller 56 is deteriorated. Therefore, in this embodiment, the timing of lowering the pickup roller 54 is set earlier than the normal timing (the timing at which the trailing edge of the previous document is detected by the register sensor SE12) for the third and subsequent documents. The condition was achieved.

Next, the main motor M3 and the discharge motor M
Turn on 4. As a result, the first document D ₁ is placed on the tray 6
Then, the second original D ₂ is conveyed to the exposure position, and the third original D ₃ is conveyed to the pre-step position [see FIG. 13 (h)]. Specifically, the counting of the number of pulses from the encoder E3 is started at the same time when the main motor M3 is turned on, the main motor M3 is turned off at the time point when n5 pulses are counted, the electromagnetic brake BRK2 is turned on, and the conveyor belt 60 is stopped. .

[0063] On the other hand, at the same time as on of the main motor M3 in this case, the same manner, by pressing the 4-sheet document D ₄ by the pickup roller 54, and turns on the sheet feed motor M2,
The document D ₄ is once made to stand by at the nip portion between the register roller 58 and the pinch roller 59a with its leading end [FIG.
(H)]. Here, image exposure is performed on the _second document D ₂ , and the paper feed motor M2 is turned on to feed the _fourth document D ₄ in advance (see FIG. 14 (i)). In this first-out paper feeding process as well, it goes without saying that the motor M2 is turned off when n1 pulses are counted after the paper feeding motor M2 is turned on.

Thereafter, the above-mentioned operation is repeatedly executed,
While the second document D ₂ is discharged onto the tray 69,
The third document D ₃ is transported to the exposure position, and the fourth document D ₄ is transported to the pre-step position [see FIG. 14 (j)]. When the image exposure for the document D ₃ is completed, the document D ₃
Is discharged onto the tray 69 and the fourth document D ₄
Is conveyed / stopped to the exposure position [see FIG. 14 (k)].
Furthermore, when the image exposure of the document D ₄ is completed, the document D ₄ is discharged onto the tray 69 [FIG.
(L)].

On the other hand, if the length of the document exceeds 216 mm, the single-sided normal mode is executed. In this case, when the rear end of the first original is detected by the register sensor SE12, the pickup roller 54 is lowered. The pulse from the encoder E3 of the main motor M3 is n after the leading edge of the first document is detected by the timing sensor SE14.
The motor M3 is turned off at the time when 7 counts are made,
The electromagnetic brake BRK2 is turned on and the conveyor belt 60 is stopped. As a result, the first document is conveyed / stopped at the exposure position where the leading edge of the first document is located at the exposure reference point O. Where 1
Image exposure is performed on the first original, and the second original is fed in advance. That is, after a lapse of a fixed time after the main motor M3 is stopped, the paper feeding motor M2 is turned on to separate the second original from the other originals, and the leading end thereof is set to the nip portion between the register roller 58 and the pinch roller 59a. Contact and correct skew. After that, the electromagnetic clutch CL is turned on, the paper feed motor M2 is turned on again, and the register roller 58 is rotated. As a result, when the second document is started to be conveyed to the first feed position and the pulse of the encoder E2, which has started counting at the same time when the feed motor M2 is turned on, counts n1 pulses, the motor M2 is turned off. The electromagnetic brake BRK1 is turned on to complete the first-out sheet feeding process for the second document.

When the image exposure of the first original is completed, the main motor M3 and the discharge motor M4 are turned on to discharge the first original onto the tray 69, and the second original is fed out at the feeding position. To the exposure position. After that, the above control is repeated until the final document is discharged onto the tray 69. In the pre-step mode, the description of the document D ₂ , D ₃ , and D _{4 in} the pre-feeding mode is omitted, but
Turn on / off the electromagnetic solenoid SL to separate the roller 5
Switching the pressure contact forces N ₁ and N ₂ between the rollers 5 and 56 and driving the separating rollers 55 and 56 during document transportation after registration is the same as the paper feeding process for the _first document D ₁ . Further, such control is also executed in the paper feed process in the one-sided normal mode.

Next, the control of the ADF 50 will be described in detail. The control is performed by the CPU 1 for controlling the main body 1 of the copying machine.
(See FIG. 16) and CPU for controlling ADF 50
2 (see FIG. 17). The CPUs 1 and 2 exchange information at necessary timings. By the way, in the explanation of the control procedure, the on-edge is a sensor,
Flags, signals, and the like mean that they are switched from the off state to the on state, and off edges mean that they are switched from the on state to the off state.

FIG. 18 shows a CPU 1 which controls the main body 1 of the copying machine.
The main routine of is shown. When the power is turned on and the CPU 1 is reset and the program starts, in step S1, the RAM is cleared, various registers are reset, and initial settings for setting various devices to the initial mode are performed. Then, in step S2, an internal timer is started. The internal timer defines the time required for one routine of this main routine, and its value is set in step S1. The internal timer serves as a reference for counting various timers that appear in each subroutine.

Next, the subroutines of steps S3 and S4 are sequentially called to perform the necessary processing, and in step S5, the end of the internal timer is awaited and the process returns to step S2. Step S3 is a subroutine for executing copy processing. In step S4, other processes such as control of the toner fixing device 40 and detection of paper jam are processed.

Further, the CPU1 is connected to the CPU2 via a serial communication line, and its transmission / reception is carried out by interrupt processing in step S6. Next, a control procedure of the CPU 2 that controls the ADF 50 will be described, but before that, a counter, a pulse, and a timer used for control there will be described. Counter PCNTM2: Encoder E of Paper Feed Motor M2
It is incremented by 1 pulse output from 2.

Counter PCNTM3a: Main motor M
It is incremented by 1 pulse output from the encoder E3 of 3. Counter PCNTM3b: Similarly, it is incremented by one pulse output from the encoder E3 of the main motor M3. Counter PSIZE: Stores the number of pulses corresponding to the length of the document.

Counter LST: Displays the number of documents located inside the ADF 50. When it is "0", it indicates that the original document is in the pre-feed position, pre-step position and exposure position, and when it is "1", the original document is in the pre-step position and exposure position (that is, the last two sheets If there is "2", it means that the original is only at the exposure position (that is, the last one).

Pulse n1: Paper feed motor M at the first feed
Number of pulses from turning on 2 to turning off 2. Pulse n3: The first document is the timing sensor SE14
The number of pulses from when the main motor M3 is turned off to stop at the pre-step position after being detected by. Pulse n5: The number of pulses from when the main motor M3 is turned on to when the document is conveyed from the pre-step position to the exposure position.

Pulse n7: The number of pulses from when the document is detected by the timing sensor SE14 to when the main motor M3 is turned off to stop at the exposure position in the single-sided normal mode. Pulse nL: The number of pulses when the document length corresponds to 216 mm. It is used to determine whether to execute the pre-step mode by comparing with the number of pulses stored in the counter PSIZE.

Timer T102: Set to the time from the detection of the leading edge of the original sent from the tray 51 by the register sensor SE12 to the contact with the nip between the register roller 58 and the pinch roller 59a to correct the skew. Has been done. Timer T103: It is set to the time from when the paper feed motor M2 is turned off to when it is stopped.

Timer T201: It is set to the time from when the electromagnetic brake BRK2 is turned on to when the conveyor belt 60 is stopped. Timer T301: Set to a time for delaying the start of document ejection. Timer T302: It is set to the time from when the trailing edge of the document is detected by the discharge sensor SE15 until the document is discharged onto the tray 69.

Timer T303: It is set to the time from when the discharge motor M4 is turned off to when it is stopped. FIG. 19 shows the main routine of the CPU 2 which controls the ADF 50. When the power is turned on, the CPU 2 is reset, and the program starts, in step S11, the RAM is cleared, various registers are reset, and initial settings for setting various devices to the initial mode are performed. Then, in step S12, an internal timer is started. The internal timer defines the time required for one routine of this main routine, and its value is set in step S11. Also,
This internal timer also serves as a reference for counting various timers that appear in the subroutine described below.

Next, the subroutines of steps S13 to S15 are sequentially called to perform the necessary processing, and then step S
At 16 the end of the internal timer is awaited and the process returns to step S12. Step S13 is a subroutine for exchanging the original on the platen glass 29. Step S14 is a subroutine for counting various timers. In step S15, other processes such as A / D conversion, input process, output process, and paper jam detection are processed.

The interrupt process for the CPU2 is performed by the main routine of the CPU2, such as various interrupt processes such as controlling the main motor M3 in step S17, and the data transmission process and data reception process with the CPU1 in steps S21 and S22 shown in FIG. It is appropriately performed regardless of the processing. FIG. 21 shows an initial setting subroutine executed in step S11.

At step S31, each data in the RAM,
Clear each counter. In step S32, the timer T
101, T103, T201, T301, T302, T
Reset 303. In step S33, each flag described below is reset. In step S34, the motors M1, M2, M3, M4, the electromagnetic solenoid SL, the electromagnetic clutch CL, and the electromagnetic brakes BRK1, BRK2 are turned off. In step S35, the internal timer is set to a predetermined value. In step S36, the paper feed status K is set to "1". In step S37, other initial settings are processed.

FIG. 22 shows a document exchange subroutine executed in step S13. In this subroutine, MODE is checked in step S40, and the following processing is performed based on the value. The MODE is initially reset to "0", and in this case, the start check is processed in step S41. In the subroutine of step S41, MODE is set to a predetermined value depending on the document conveyance mode selected by the operator. (See FIG. 23, steps S68, S69, S70).

When the MODE is "1", the mode is the one-sided document transport mode, and in step S42, the document is transported from the tray 51 to the pre-feeding position. Subsequently, in step S43, a pre-step feed for transporting the one-sided original to the pre-step position and the exposure position, or a single-sided normal feed for directly transporting the one-sided original to the exposure position is processed. Further, in step S44, the document is discharged from the exposure position to the tray 69.

When the MODE is "2", the mode is the double-sided document transport mode, the paper feed is processed in step S45, and the double-sided document is set at the exposure position in step S46.
In step S47, the paper discharge is processed. Details of these processes are omitted. When the MODE is "3", the mode is 2-in-1 mode. 2-in-1 mode is one of two originals
This is a copy mode in which two sets of original images are formed on one copy sheet by continuously arranging them as a set on the platen glass 29. Here, paper feeding is processed in step S48, two originals are set on the platen glass 29 in step S49, and paper is discharged in step S50. Details of these processes are omitted.

FIG. 23 shows a start check subroutine executed in step S41. This subroutine is processed when MODE is "0", that is, when the ADF 50 is in a standby state. First, in step S61, it is determined whether or not the empty sensor SE11 is on. If it is not turned on, it means that the original has not been set on the tray 51 yet, and this subroutine is immediately terminated.
When the sensor SE11 is turned on (when a document is set on the tray 51), it is determined in step S62 whether the flag DCHG is "1". The flag DCHG is a command for requesting document replacement when it is "1", and the CPU 1
Sent from. This flag DCHG is "1" at the time when the print key is turned on and the image scan for the number of copies is completed.
Is set to. Therefore, if the flag DCHG is "1", the flag DCHG is reset to "0" in step S63, and the paper feed status K is "3" in step S64.
Set to and return. The status K is used in the paper feed subroutine and is set to "3" to start the paper feed process.

On the other hand, when the sensor SE11 is on, the flag D
If CHG is "0", it is determined in step S65 whether the status K is "2" and in step S66 whether the status K is "20". If the status K is "2", that is, if the return of the pickup roller 54 to the home position is completed, as described below,
If it is other than "20", this subroutine is terminated. If the status K is "20", that is, after the first original has been fed in advance as described below, the original mode is checked in step S67.
If it is single-sided mode, MODE is set to "1" in step S68.
, And if it is the double-sided mode, then at step S69, MO
The DE is set to "2", and in the 2-in-1 mode, the MODE is set to "3" in step S70. continue,
In step S71, the set status S used when setting the original on the platen glass 29 is set to "1", and this subroutine is finished.

24 to 27 show a paper feeding subroutine executed in step S42. In this subroutine, the paper feed status K is checked in step S80, and the following processing is performed based on the values "0" to "8" and "20". The status K is initially reset to "0" and no processing is performed at this time.

When the status K is "1" (see step S36 of initial setting), the pickup roller 54 is returned to the upper home position. First, step S
At 81, the pickup motor M1 is turned on, and step S8 is performed.
At 2, the electromagnetic solenoid SL is turned off. When the off edge of the pickup sensor SE10 is confirmed in step S83, it is determined that the pickup roller 54 has returned to the home position, the motor M1 is turned off in step S84, and the status K is set to "2" in step S85. When the status K is "2", nothing is processed,
stand by.

When the status K is "3" (see step S64 for start check and steps S215, S230, S336 for single-sided document setting), document feeding is started. First, in step S91, the pickup motor M1 is turned on. Here, when the pickup roller 54 descends and the on-edge of the sensor SE10 is confirmed in step S92, the pickup roller 54 descends to a predetermined position, so the motor M1 is turned off in step S93.
At step S94, the paper feed motor M2 is turned on, and then step S
At 95, the electromagnetic solenoid SL is turned on. As a result, the first pressure contact force N ₁ acts between the separating rollers 55 and 56.
At the same time, the pickup roller 54, the sorting roller 55,
56 rotates, the document is sent out from the tray 51, separated into the uppermost one sheet, and goes to the register roller 58.
The original conveying speed at this time is the first speed V ₁ , and the original is separated by the appropriate pressure contact force N ₁ between the separating rollers 55 and 56. Further, the status K is set to "4" in step S96.

When the status K is "4", it is determined in step S101 whether the register sensor SE12 is on edge or not.
(If detected in E12), the timer T is detected in step S102.
102 is set, and the electromagnetic brake B is set in step S103.
Turn on RK1. This locks the register roller 58. Then, the status K is set to "5" in step S104.

When the status K is "5", the timer T102 is waited for in step S111, and then step S111 is executed.
At 112, the paper feed motor M2 is turned off. Here, the leading edge of the original comes into contact with the nip portion between the register roller 58 and the pinch roller 59a to form a predetermined amount of loop, and skew feeding is corrected. Subsequently, the timer T103 is set in step S113, and the status K is set to "6" in step S104.

When the status K is "6", the timer T103 is waited for in step S121 and then step S1 is executed.
The electromagnetic clutch CL is turned on at 22 and the electromagnetic brake BRK1 is turned off at step S123. Thus, the register roller 58 can be rotationally driven by the paper feeding motor M2. Then, in step S124, the counter PCNTM2
Is reset to "0", the electromagnetic solenoid SL is turned off in step S125, and the sheet feeding motor M2 is set in step S126.
Is turned on, and in step S127, the pickup motor M1
Is turned on, and the status K is set to "7" in step S128. With the original by-one of the feed motor M2 is started the conveyance at the speed V ₁ second velocity V ₂ faster than by the register rollers 58, the number of pulses from the encoder E2 PCNTM2 starts counting. Further, when the pickup motor M1 is turned on, the pickup roller 54 starts returning upward. On the other hand _{, when the} electromagnetic solenoid SL is turned off, the second pressure contact force N ₂ acts between the separating rollers 55 and 56.
The second pressure contact force N ₂ is smaller than the first pressure contact force N ₁ ,
The original is moved by the register roller 58 to a second speed V of high speed.
It works to improve the separation performance for the next original when it is conveyed in ₂ . Further, in the post-registration conveyance, the separating rollers 55 and 56 are driven to rotate,
The loop at the front end of the document is gently resolved, and the loop elimination sound and the occurrence of damage to the document are avoided.

When the status K is "7", it is determined in step S131 whether the count value of PCNTM2 is n1. Normally, before the PCNTM2 counts n1 (NO in step S131), the sensor SE10 is determined to be off-edge in step S135, and step S13 is performed.
At 6, the pickup motor M1 is turned off. This means that the pickup roller 54 has returned to the home position. When PCNTM2 counts n1, the paper feed motor M2 is turned off in step S132, the electromagnetic brake BRK1 is turned on in step S133, and the status K is set to "8" in step S134. As a result, the rotation of the register roller 58 is stopped, and the document pre-feeding is completed. At this time, the document is stopped when the leading edge reaches the advance reference point P.

When the status K is "8", the count value of PCNTM2 is stored in PSIZE in step S141. Subsequently, in step S142, the electromagnetic clutch C
L is turned off, and in step S143, the electromagnetic brake BRK1
Turn off. As a result, the register roller 58 is disconnected from the paper feed motor M2 and is free. Further, the status K is set to "20" in step S144.

When the status K is "20", the first-out paper feeding of the original document has been completed, and the process stands by without performing any processing. 28 to 38 show a subroutine executed in step S43 for setting the one-sided original at a predetermined position on the platen glass 29. In this subroutine, step S
The set status S is checked at 170, and the following processing is performed based on the values "0" to "16".

When the status S is "0" (initial state), MODE is reset to "0" in step S171, and the paper feed status K is set to "2" in step S172. When the status S is "1" (paper feeding complete,
(See steps S66 and S71), the main motor M3 is turned on in step S175, and the status S is set to "2" in step S176. Here, the register roller 58 and the conveyor belt 60 are rotationally driven, and the original document fed in advance starts to be carried onto the platen glass 29.

When the status S is "2", when the on edge of the timing sensor SE14 is confirmed in step S181, that is, when the leading edge of the document is detected by the sensor SE14, the encoder E3 of the main motor M3 is detected in step S182. PC that counts the number of pulses output from the
The NTM3a is reset to "0" and the counting is started. Subsequently, in step S183, the status S is set to "3".

When the status S is "3", if the off edge of the register sensor SE12 is confirmed in step S191, that is, the trailing edge of the document is detected by the sensor SE12, the count value of PSIZE (in step S192). Step S141) and PCNTM3 at that time
The count value of a is added and stored in PSIZE. This count value corresponds to the length of the document. Then, in step S193, PSIZE is compared with the pulse nL. nL
Is the number of pulses corresponding to a document length of 216 mm,
If PSIZE <nL, the status S is set to "4" in step S194, and the prestep mode is executed. If PSIZE ≧ nL, the status S is set to “14” in step S195, and the single-sided normal mode is executed.

When the status S is "4", when it is confirmed in step S201 that the count value of PCNTM3a has reached n3, the main motor M3 is turned off in step S202, and the electromagnetic brake BRK2 is turned on in step S203. . Thus, the document is set at the prestep position. Subsequently, the timer T201 is set in step S204, and the status S is set to "5" in step S205.

When the status S is "5", after confirming the end of the timer T201 in step S211, that is,
After the conveyor belt 60 is completely stopped, step S212
Then, the electromagnetic brake BRK2 is turned off. Subsequently, in step S213, it is determined whether the empty sensor SE11 is on or off. If the sensor SE11 is on, there is the next original on the tray 51, so the paper feed status K is set to "3" in step S215, and the status S is set to "6" in step S216. If the sensor SE11 is off, all the originals on the tray 51 have been fed, so the LST is set to "1" in step S214, and the status S is set to "6" in step S216.

When the status S is "6", it is determined in step S221 whether the paper feed status K is "20". If the status K is set to "20", it means that the pre-feeding of the next original has been completed, and the step S2 is performed.
22 reset PCNTM3b to "0" and
Start the count. Then, step S223.
Then, it is determined whether the flag DSET is "1". Flag D
SET indicates that the document is set at the exposure position (see step S264). If the flag DSET is "0", the process proceeds to step S226. If the flag DSET is "1", the flag DSET is reset to "0" in step S224, and in step S225, a sheet discharge used for discharging the document to the tray 69. The status H is set to "1", and the process proceeds to step S226.

In step S226, the main motor M3 is turned on, and in step S227, the value of the counter LST is checked. LST indicates the number of originals in the ADF 50. If the original is "0", the original is present at the first paper feed position. In this case, the paper feed status K is "3" in step S228.
, And set the status S to “7” in step S229.
Set to. As a result, at the same time when the main motor M3 is turned on in step S226, the advance feeding of the third and subsequent documents is started. If LST is not "0", there is no document at the first paper feed position. In this case, LST is incremented and set to "1" in step S230, and status S is set to "9" in step S231.

When the status S is "7", when the on-edge of the timing sensor SE14 is confirmed in step S235, that is, when the leading edge of the document is detected by the sensor SE14, the PCNTM3a is set to "0" in step S236.
Resets to and starts counting. Here, the measurement of the conveyance amount of the next document to the pre-step position is started. Then, in step S237, the status S
Is set to "8".

When the status S is "8", when the off edge of the register sensor SE12 is confirmed in step S241, that is, when the trailing edge of the document passes the detection point of the sensor SE12, the empty sensor S12 is detected in step S242.
It is determined whether E11 is on or off. If the sensor SE11 is on, there is the next original on the tray 51, so the status S is set to "9" in step S243, and the operation of stopping the original is started. If the sensor SE11 is off,
Since all the documents on the tray 11 have been fed, step S
At 244, the paper feed status K is set to "1", and at step S245, the counter LST is set to "1".

When the status S is "9", when it is confirmed in step S251 that the count value of PCNTM3b has reached n5, the main motor M3 is turned off in step S252, and the value of the counter LST is checked in step S253. . If LST is other than “2”, that is,
If at least two originals are present on the platen glass 29 before the original is conveyed here, the electromagnetic brake BRK2 is turned on in step S254, and the timer T201 is set in step S255. If LST is “2”,
Since only the final document exists at the exposure position before the document is transported here, the timer T2 is set in step S255 without turning on the electromagnetic brake BRK2 (for document ejection).
Set 01. Then, the status S is set to "10" in step S256.

When the status S is "10", after confirming the end of the timer T201 in step S261, that is, after the conveyor belt 60 is completely stopped, step S2
At 62, the electromagnetic brake BRK2 is turned off. Then, in step S263, the value of the counter LST is checked,
If "2", that is, if only the final document exists at the exposure position, LST is reset to "0" in step S266, and status S is set to "0" in step S267.
To reset this subroutine. If LST is other than "2", if at least two originals are present on the platen glass 29, step S2.
At 64, the flag DSET is set to "1". Flag D
SET indicates that the document is set at the exposure position. Furthermore, the status S is set to "1" in step S265.
Set to 1 ”.

When the status S is "11", the flag DCHG is "1" in step S281 (request for document replacement), and the paper feed status K is "20" in step S282 (first-out paper feed). , And that the paper discharge status H is “6” in step S283 (paper discharge completion), and then the flag D in step S284.
CHG is reset to "0", and the status S is set to "6" in step S285. With this, the document replacement process is restarted.

When the status S is "12" (when the one-sided normal mode is executed, see step S355), it is determined in step S291 whether the flag DSET is "1". If "0", the main motor M3 is turned on in step S294. If "1", that is, if the document is set at the exposure position, step S292.
To reset the flag DSET to "0", and step S2
The discharge status H is set to "1" at 93, and the main motor M3 is turned on at step S294. This starts the discharge of the original document from the exposure position. Then, in step S295, the value of the counter LST is checked. LS
When T is "0", the next original is fed in advance, so the status S is set to "13" in step S296. If LST is not "0", that is, if there is no document at the first-out paper feeding position, then PCNT is entered in step S297.
The M3a is reset to "0" and the counting is started. Then, in step S298, the status S
Is set to "14".

When the status S is "13", when the on-edge of the timing sensor SE14 is confirmed in step S301, that is, when the leading edge of the document is detected by the sensor SE14, the PCNTM3a is set to "0" in step S302. Reset and start counting. Then, in step S303, the status S is set to "1.
4 ”.

When the status S is "14", if it is confirmed in step S311 that the count value of PCNTM3a has reached n7, the main motor M3 is turned off in step S312, and the value of the counter LST is checked in step S313. . If LST is not “1”, that is,
Since the next document is in the first-out paper feeding position, step S3
In step 14, the electromagnetic brake BRK2 is turned on, and step S31
Go to 5. If LST is "1", that is, there is no original document at the first feeding position and only the last original document is set at the exposure position. Therefore, with the electromagnetic brake BRK2 kept off, the timer T201 is set at step S315. Set and set status S to "15" in step S316
Set to.

When the status S is "15", after confirming the end of the timer T201 in step S331, that is, after the conveyor belt 60 is completely stopped, step S3 is performed.
At 32, the electromagnetic brake BRK2 is turned off. Then, in step S333, the value of the counter LST is checked. L
If ST is not "1", that is, if the next document is set at the first-out paper feeding position, the next document is set at the exposure position, and therefore the flag DSET is set at step S334.
Is set to "1". Further, in step S335, it is determined whether or not the empty sensor SE11 is on. If the sensor SE11 is on and the document remains on the tray 51,
The paper feed status K is set to "3" in step S336, and the status S is set to "16" in step S338. If the sensor SE11 is off and the document does not remain on the tray 51, the document is currently set only at the exposure position. Therefore, LST is set to "1" in step S337, and status S is set to "16" in step S338. Set to. On the other hand, if LST is "1" (YES in step S333), that is, since the final document has been ejected, LST is reset to "0" in step S339.
In step S340, the status S is reset to "0", and this subroutine is finished.

When the status S is "16", the flag DCHG is "1" in step S351 (original replacement request), and the paper feed status K is "20" in step S352 (previous feed). Completion) and that the discharge status H is "6" in step S353 (completion of discharge), and then the flag D is determined in step S354.
CHG is reset to "0", and the status S is set to "12" in step S355. With this, the document replacement process is restarted.

39 to 41 show a subroutine for processing document discharge, which is executed in step S44. Here, the paper discharge status H is checked in step S370, and the following processing is performed based on the values "0" to "6". When the status H is “0”, it is the initial state,
Do nothing

When the status H is "1" (when the document starts to be discharged from the exposure position, steps S225, S2
93), the timer T301 is set in step S371, and the status H is set to "2" in step S372. The timer T301 is for delaying the drive of the discharge motor M4 until just before the leading edge of the document reaches the reverse / discharge roller 65.

When the status H is "2", when the end of the timer T301 is confirmed in step S375, the discharge motor M4 is turned on in step S376, and step S3 is executed.
At 77, the status H is set to "3". At this time, the reversing / ejecting roller 65 and the ejecting roller 68 start rotating, and the document starts to be ejected onto the tray 69. When the status H is "3", the discharge sensor S is detected in step S381.
After confirming the off edge of E15, that is, when the trailing edge of the document is detected by the sensor SE15, the timer T302 is set in step S382, and the status H is set to "4" in step S383.

When the status H is "4", after confirming the end of the timer T302 in step S385, that is,
After the original is completely discharged onto the tray 69, step S
At 386, the discharge motor M4 is turned off. Further, the timer T303 is set in step S387, and step S38
At 8, the status H is set to "5". Status H
Is "5", the timer T303 is set in step S391.
After confirming the end of step 1, that is, when the discharge motor M4 is completely stopped, the status H is set to "6" in step S392.

When the status H is "6", nothing is processed and the process stands by. The sheet conveying device according to the present invention is not limited to the above-mentioned embodiment, but can be variously modified within the scope of the gist.

[Brief description of drawings]

FIG. 1 is an automatic document feeder (A according to an embodiment of the present invention.
DF) and a schematic configuration diagram of the copying machine body.

FIG. 2 is a sectional view showing an internal configuration of an ADF.

FIG. 3 is a front view of a document separating mechanism, showing a state before document registration.

FIG. 4 shows a front view of a document separating mechanism and after document registration.

FIG. 5 is a sectional view of a separating roller.

FIG. 6 is an explanatory diagram showing a contact state of a separating roller.

FIG. 7 is an explanatory diagram when one sheet is interposed between the separating rollers.

FIG. 8 is an explanatory diagram when one sheet is interposed between the separating rollers.

FIG. 9 is an explanatory diagram when two sheets are interposed between the separating rollers.

FIG. 10 is a graph showing the relationship between torque Ts and roller pressure contact force N.

FIG. 11 is a graph showing the relationship between torque Ts and roller pressure contact force N.

FIG. 12 is an explanatory diagram showing document transportation in a pre-step mode.

FIG. 13 is an explanatory diagram showing document transportation in the pre-step mode, continued from FIG. 12;

FIG. 14 is an explanatory diagram showing document transportation in the pre-step mode, continued from FIG.

FIG. 15 is a block diagram showing a drive system.

FIG. 16 is a block diagram showing a CPU 1 that controls a copying machine main body.

FIG. 17 is a block diagram showing a CPU 2 that controls an ADF.

FIG. 18 is a flowchart showing a main routine of CPU 1.

FIG. 19 is a flowchart showing a main routine of CPU2.

FIG. 20 is a flowchart showing a subroutine of interrupt processing in the CPU 2.

FIG. 21 is a flowchart showing an initial setting subroutine in the CPU 2.

FIG. 22 is a flowchart showing a subroutine of document exchange in CPU2.

FIG. 23 is a flowchart showing a start check subroutine in the CPU 2.

FIG. 24 is a flowchart showing a paper feeding subroutine in the CPU 2.

FIG. 25 is a flowchart showing a paper feeding subroutine in the CPU 2, following FIG. 24.

FIG. 26 is a flowchart showing a paper feeding subroutine in the CPU 2, continuing from FIG. 25.

FIG. 27 is a flowchart showing a paper feeding subroutine in the CPU 2, continuing from FIG. 26.

FIG. 28 is a flowchart showing a single-sided original setting subroutine in the CPU 2.

FIG. 29 is a flowchart showing a subroutine for single-sided original setting in CPU 2, following FIG. 28;

FIG. 30 is a flowchart showing a subroutine for single-sided document setting in CPU 2, following FIG. 29;

FIG. 31 is a flowchart showing a subroutine for single-sided original setting in CPU 2, following FIG. 30;

FIG. 32 is a flowchart showing a subroutine for single-sided original setting in the CPU 2, following FIG. 31.

FIG. 33 is a flowchart showing a subroutine for single-sided document setting in CPU 2, following FIG. 32;

FIG. 34 is a flowchart showing a single-sided original setting subroutine in the CPU 2, following FIG. 33;

FIG. 35 is a flowchart showing a subroutine for single-sided document setting in CPU 2, following FIG. 34;

FIG. 36 is a flowchart showing a subroutine for single-sided original setting in the CPU 2, following FIG. 35;

FIG. 37 is a flowchart showing a subroutine for single-sided document setting in CPU 2, following FIG. 36.

FIG. 38 is a flowchart showing a subroutine for single-sided document setting in CPU 2, continuing from FIG. 37.

FIG. 39 is a flowchart showing a paper discharge subroutine in the CPU 2.

FIG. 40 is a flowchart showing a paper discharge subroutine in the CPU 2, following FIG. 39;

FIG. 41 is a flowchart showing a paper discharge subroutine in the CPU 2, following FIG. 40.

[Explanation of symbols]

 50 ... Automatic document feeding device 54 ... Pickup roller 55 ... Forward rotation sorting roller 56 ... Reverse rotation sorting roller 58 ... Register roller 59a ... Pinch roller 83 ... Lever 84 ... Coil spring 85 ... Adjustment lever 86 ... Coil spring TL ... Torque limiter M2 ... Paper feed motor M3 ... Main motor SL ... Electromagnetic solenoid CL ... Electromagnetic clutch SE12 ... Register sensor CPU2 ... Microcomputer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical indication location G03G 15/00 108 7369-2H (72) Inventor Tomoyuki Atsumi 2-chome, Azuchi-cho, Chuo-ku, Osaka-shi, Osaka No. 3-13 Osaka International Building Minolta Camera Co., Ltd.

Claims (3)

[Claims] 1. A pick-up unit for applying a conveying force in one direction to a sheet in a stacked state while pressing it, a forward rotation member for conveying the sheet, and a sheet for conveying the sheet to be separated into one sheet. Separating means for separating the picked-up sheets into one sheet and conveying the picked-up sheets to the downstream side, and first driving means for driving the separating means. A conveying unit that is located downstream of the separating unit and that conveys the separated sheet to a further downstream side; a second driving unit that drives the conveying unit; the forward rotating member and the separating member. And a first pressure required to separate the sheet when the sheet is conveyed at the first speed by the forward rotation member, and when the sheet is conveyed at the second speed by the conveying unit. Required to separate the paper into After a certain period of time after which the pressurizing means for selectively acting the second pressure and the leading edge of the sheet separated into one sheet by the separating means driven by the first driving means come into contact with the conveying means, the conveying means. Between the normal rotation member and the separating member, the first control means driving the separating means by the first driving means for a predetermined time after the conveyance of the sheet is started by the second driving means. In addition, the first pressure acts until the conveying means receives the driving force from the second driving means, and the second pressure remains after the conveying means receives the driving force from the second driving means. A second control means for controlling the pressurizing means so as to operate. 2. A clutch member, wherein the first driving means and the second driving means have the same driving source, and the second driving means selectively transmits the driving force from the driving source to the conveying means. The sheet conveying apparatus according to claim 1, further comprising: 3. The second speed of the transport means is set to be higher than the first speed of the normal rotation member, and the normal rotation member causes the first drive means to move the sheet to the downstream side at the first speed. Is a roller that is driven to rotate at a second speed when the sheet is conveyed at a second speed by the conveying unit, and the separating member is a roller that can push back the sheet to the upstream side. The first pressure rotates when the separating member pushes the paper back to the upstream side by the first driving means when two or more sheets are interposed between the normal rotation member and the separating member. When a sheet of paper intervenes, it is set to a value that rotates following the conveyance of the paper to the downstream side, and the second pressure is set to be smaller than the first pressure. The sheet conveying device according to claim 1.