JPH10250865A - Automatic document conveying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To separate many kinds of documents stably by making the tip of a flexible member enter the contact faces of a separating roller and a separating belt at the time of separating thick documents and face curled documents, and retreating the tip of the flexible member from the contact faces of the separating roller and separating belt at the time of separating thin documents and back curled documents. SOLUTION: The tip of a flexible member 119 with a low friction coefficient, fixed to a document keep plate 118 is made movable between a position of entering the contact faces of a separating roller and a separating belt and a position of retreating from the contact faces. At the time of separating thick documents and face curled documents, the tip of the flexible member 119 is made to enter the contact faces of the separating roller and separating belt so as to make the tip of a document sheaf enter the contact faces of the separating roller and separating belt smoothly and positively. At the time of separating thin documents and back curled documents, the tip of the flexible member 119 is retreated from the contact faces of the separating roller and separating belt so as to make it easy for the tip of the document sheaf to butt the separating belt, thus preventing overlap feed of the documents.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic document feeder applied to a copying machine, a facsimile machine, a scanner, and the like. More specifically, the present invention relates to a sheet bundle of fed sheets separated by a separation roller and a separation belt unit. The present invention relates to an automatic document feeder that is separated and conveyed to a reading position.

[0002]

2. Description of the Related Art Generally, an automatic document feeder (hereinafter, simply referred to as an ADF) used for an image reading device such as a facsimile machine, a copying machine, a scanner device, etc. is mounted on a document mounting table for the purpose of miniaturization. The set of originals is fed to a reversing path for reversing the originals by a pickup roller, and the originals are separated one by one by a separation belt and a separation roller provided on the reversing path, and the original surface is placed on a contact glass. Is transported in reverse.

[0003] Documents to be separated include documents having different paper thicknesses, such as thick paper and thin paper, and curled documents such as back curls and face curls. When a document bundle is separated by the above-described separation belt and separation rollers, such a document is separated. In order to reliably separate various originals, the contact angle of the contact surface between the separation belt and the separation roller is made variable.
More specifically, a bracket that supports the separation belt so as to be able to move around the separation belt can be tilted and a tilting member that tilts the bracket is provided, and when a document such as a thick paper document or a face curl document is easily separated, non-feeding is likely to occur. The bracket is tilted so that the contact angle between the separation belt and the separation roller is reduced, so that the document can easily enter the contact surface between the separation belt and the separation roller.

Also, when separating a multi-feed original such as a thin paper original or a back-curled original, a bracket is raised so that the contact angle between the separation belt and the separation roller is increased so that the leading end of the original strikes the separation belt. To prevent double feed. On the other hand, in order to improve the document separation performance, in addition to varying the angle of the separation belt, it is important to make the leading edge of the document smoothly enter the contact surface between the separation roller and the separation belt. In the document, a flexible member having a low coefficient of friction is provided on the upstream side of the separation roller in the document conveying direction, and the flexible member guides the leading end of the document to the contact surface between the separation roller and the separation belt.

Since the separation belt orbits in the direction in which the document is conveyed and the separation roller rotates in the direction for preventing the separation of the document, the tip of the flexible member is contacted to the contact surface between the separation roller and the separation belt. The separation performance of the document is greatly affected by whether the document is to be entered.

[0006]

However, since the flexible member is fixed in such a conventional ADF, when the flexible member is fixed in accordance with the thick paper document or the face curl document, the thin paper document is not fixed. When a flexible member is fixed to a thin paper or back curled original, non-feeding is likely to occur when separating a thick paper or face curled original. As a result, there is a problem that the separation performance of the document becomes unstable.

Accordingly, the present invention can prevent the occurrence of non-feed when separating a thick paper document or a face-curled document, and prevent the occurrence of non-feed when separating a thin paper document or a back-curled document. SUMMARY OF THE INVENTION It is an object of the present invention to provide an automatic document feeder with high separation performance capable of stably separating various types of documents.

[0008]

According to the first aspect of the present invention,
In order to solve the above problem, an automatic document feeder configured to separate a fed sheet bundle by a separation roller and a separation belt unit one by one and to convey the sheet bundle to a reading position, wherein the separation belt unit includes: A separation belt that comes into contact with the separation roller, a bracket that supports the separation belt so as to be able to move around the separation belt, and a low coefficient of friction that is supported by the bracket and guides a bundle of documents to be fed to the contact surface between the separation roller and the separation belt. A flexible member, wherein the flexible member is movable between a position where the tip of the flexible member enters a contact surface of the separation roller and the separation belt and a position where the tip of the flexible member retreats from the contact surface.

In this case, when separating a thick paper document or a face curl document, the leading end of the flexible member is caused to enter the contact surface between the separation roller and the separation belt so that the leading end of the bundle of documents is brought into contact with the separation roller and the separation belt. It is possible to smoothly and reliably enter the apparatus, and it is possible to prevent the document from being non-fed. When separating a thin paper document or a back-curled document, the leading edge of the flexible member is retracted from the contact surface between the separating roller and the separating belt, so that the leading edge of the bundle of documents can be easily abutted against the separating belt, so that multiple feeds of the document can be performed. This can be prevented from occurring.

As a result, it is possible to stably separate various types of originals, and to improve the separation performance of the originals. According to a second aspect of the present invention, in order to solve the above problem, in the first aspect of the present invention, the flexible member guides the original bundle to be fed to the contact surface between the separation roller and the separation belt. And the document pressing plate is movably supported by the bracket so as to be located on the upstream side in the document conveying direction with respect to the flexible member.

In this case, since the document holding plate is provided, a high (thick) document bundle can be smoothly guided by the document holding plate to the contact surface between the separation roller and the separation belt. According to a third aspect of the present invention, in order to solve the above problem, in the second aspect of the present invention, both ends of the document pressing plate are engaged with a bracket.

According to a fourth aspect of the present invention, in order to solve the above-mentioned problems, in the second aspect of the invention, a long hole is formed in the document pressing plate extending along a document conveying direction. The bracket is provided with a fixing member that is inserted into the elongated hole and fixes the document pressing plate to the bracket. In the case of the invention according to claim 3 or 4, by moving the document pressing plate with respect to the bracket, the position where the leading end of the flexible member enters the contact surface between the separation roller and the separation belt and the position where it retracts from the contact surface. Can be moved between.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 8 are views showing an embodiment of an automatic document feeder according to the present invention. In this embodiment, an example in which the automatic document feeder is applied to a copying machine as an image reading apparatus is shown, but the present invention can also be applied to a facsimile apparatus or a scanner as an image reading apparatus.

First, the configuration will be described. 1 and 2, reference numeral 1 denotes an automatic document feeder (hereinafter, referred to as an ADF). The ADF 1 has a contact glass 2 provided above a copying machine (not shown) as an image reading device and constituting a part of a reading position. Covering. The ADF 1 includes a document table 3 on which a document bundle composed of a plurality of documents can be placed, and a lowermost document separated from the document stack on the document table 3 one by one and fed. Separating / transporting means 4 for transporting toward the glass 2, transporting means 5 for transporting the document separated and transported from the separating / transporting means 4 to a document reading position on the contact glass 2, and exposure on the contact glass 2 Paper discharge means 7 having a paper discharge path for discharging the copied document onto the document discharge section 6 and a turn path for reversing the document during double-sided document copy and returning it to the contact glass 2 again;
It has.

When the original bundle is set on the original table 3, the separating / transporting means 4 comes into contact with the leading end of the original bundle to prevent the original bundle from entering inward.
A document set detection filler 9 that moves upward by contacting the leading end of the document bundle set on the document mounting table 3, a document set sensor 10 that detects the detection filler 9 in proximity to and separated from the detection filler 9, Detection filler 9 is a set sensor
When the sensor 10 detects separation from the sensor 10, the pressing lever 12 approaches the call roller 11 and presses the document bundle against the call roller 11 to feed the document bundle together with the call roller 11.
It has.

The original stopper 8 and the pressing lever are driven by a drive shaft.
13, and can be swung by the drive shaft 13. The drive shaft 13 is connected to a call solenoid 17, and the solenoid 17 is driven by a main control unit 18. This main control unit 18
U (Central Processing Unit) 18a, RAM (RandomAc
The ADF 1 includes a basic memory (access memory), a read only memory (ROM), and the like.

When the lever 17a is constantly urged by the spring 17b, the ringing solenoid 17 rotates the pivot shaft 13.
Is rotated to a predetermined position. In this state, the original stopper 8 prevents the original bundle from entering and the pressing lever
12 is separated from the ring 11. That is, the calling solenoid 17 is formed of a keep solenoid, and the plunger once pulled is kept as it is by the magnetic force of the keep solenoid.

The calling solenoid 17 detects that the original set sensor 10 has set the original bundle, outputs a signal from the set sensor 10 to the main controller 18 and depresses the start switch. When turned on based on a signal from the main control unit 18, the rotating shaft 13 is rotated in a direction opposite to a predetermined direction against the urging force of the spring 17b, and the document stopper 8 is separated from the leading end of the document bundle. At the same time, the holding lever 12 is brought into contact with the recall roller 11 via the document bundle.

The pressing lever 12 is pressed by a compression spring (not shown) so as to press the original bundle with a sufficient pressing force when it comes into contact with the call roller 11 via the original bundle. A pull-out driven roller 21 abutted by a spring (not shown) on the separation roller 19, the separation belt 20, the pull-out drive roller 21, and the pull-out drive roller 21 is located downstream of the retrieving roller 11 in the document conveying direction.
a is provided. The separation belt 20 is formed of an endless belt, and is driven by a separation belt driving roller 22.

The bundle of originals fed by the retrieving roller 11 is temporarily stopped between the separation roller 19 and the separation belt 20, and then the lowermost document is separated from the separation roller 19 and the separation belt.
After being separated by the frictional force of 20, the separation roller 19 and the pull-out drive roller 21 convey the sheet toward the contact glass 2. When the leading end of the bundle of documents conveyed toward the contact glass 2 is detected by the registration sensor 100, the driving of the calling roller 11 and the separation roller 19 is stopped, and the separation belt 20 and the pull-out driving roller 21 move the document. It is conveyed toward the contact glass 2.

The above-described call roller 11, separation roller 19, separation belt 20, and pull-out drive roller 21 are driven via a transmission mechanism 24 by a paper feed motor 23 which is a stepping motor of the present invention. That is, the driving force of the paper feed motor 23 is controlled by the driven pulley via the timing belt 25.
The driven pulley 26 transmits a driving force to a pulley 28 via a connecting shaft 27. The pulley 28 transmits a driving force to a pulley 30 via a timing belt 29.
Numeral 30 transmits a driving force to gears 32 and 33 via a rotating shaft 31. The gear 32 is connected to the separation belt driving roller 22 via a gear group 34 and a rotating shaft 35, and the gear 32 is rotatable only in a counterclockwise direction by a one-way clutch. The gear 32 is connected to a gear 37 rotatable only in a counterclockwise direction by a one-way clutch via an idler gear 36. The pull-out drive roller 21 is connected.

On the other hand, the gear 33 is rotatable only clockwise by a one-way clutch.
The gear 40 is connected to the separation roller 19 via a rotating shaft 41. The gear 33 is also meshed with a gear 39, and this gear 39 is a gear that can be rotated only in a counterclockwise direction by an one-way clutch via an idler gear 42.
43, and this gear 43
Connected to 11.

Accordingly, when the paper feed motor 23 is rotated clockwise in FIG. 2, the paging roller 11, the separation roller 19 and the pull-out drive roller 21 rotate counterclockwise with the separation belt 20 stopped. When the bundle of originals is fed and separated, and the leading edge of the separated originals is detected by the registration sensor 100, the feed motor
After the stoppage, the sheet feeding motor 23 rotates counterclockwise in FIG. 2 to stop the rotation of the calling roller 11 and the separation roller 19, and the separation belt 20 and the pull-out drive roller 21 rotate and follow. The separated original is conveyed toward the contact glass 2 while preventing the separated original from being separated.

The paper feed motor 23 is constituted by a four-phase stepping motor. The torque and the rotation speed of the paper feed motor 23 are controlled by a motor driver (not shown), and the motor driver is controlled by the main controller 18. It has become. The motor driver varies the pulse width of the signal supplied to each coil of the paper feeding motor based on the four-phase input signal input from the main control unit 18 to vary the rotation speed of the paper feeding motor 23. ing.

The registration sensor 100 detects the front and rear ends of the document and outputs a signal to the main control unit 18. Reference numeral 102 denotes a document width detection sensor.
02 is configured to detect the length of the document in the width direction and output document size information to the main control unit 18. A pulse generator (not shown) is provided on the rotation shaft of the pull-out driven roller 21a, and a pulse generated by the pulse generator is detected by the document length detection sensor 103. The detection signal from the sensor 103 is output to the main control unit 18.

Further, the main control unit 18 controls the registration sensor 10
When the detection information of the front and rear ends of the original is input by 0, the pulse signal of the motor driver that drives the paper feed motor 23 when passing the front and rear ends is counted, and the original length is determined by the original feed amount per pulse. Calculation and determination. Then, the main controller 18 finally detects the document length based on the detection information from the registration sensor 100 and the pulse signal of the paper feed motor 23. In addition, paper feed motor
Instead of counting the number of pulses of 23 and detecting the rotation amount of the pull-out driving roller 21, the rotation amount of the rotating shaft of the pull-out driving roller 21 may be detected by a pulse generator and a sensor.

On the other hand, the conveying means 5 inserts the original between the driving roller 51 and the driven roller 52, the endless conveying belt 53 wound around the rollers 51 and 52, and the conveying belt 53 and the contact glass 2. And a plurality of rows of pressing rollers 55 which are provided so as to be separated by a predetermined distance in the extending direction of the contact glass 2 and press the conveyor belt 53 against the contact glass 2. I have.

The transport means 5 transports the original to the reading position by the transport belt 53 and transports the exposed original from the contact glass 2 to the paper discharge means 7. The drive roller 51 is connected to a transport belt motor 58 via a transmission mechanism 57, and is driven by the transport belt motor 58. The transport belt motor 58 is connected to a driven pulley 60 via a timing belt 59, and the driven pulley 60 transmits the driving force of the transport belt motor 58 to a pulley 62 via a timing belt 61. The pulley 62 is connected to the driving roller 51 via a rotating shaft 63, and transmits the driving force from the conveyor belt motor 58 by the above-described members.

The conveyor belt motor 58 is driven by the main controller 18 in the counterclockwise direction in FIG. 2 so that the original is transported together with the separation belt 20 and the pull-out driving roller 21 toward the original reading position of the contact glass 2. When a signal indicating that the trailing end of the document separated from the registration sensor 100 has been detected is input to the main control unit 18, the number of set pulses after the drive of the sheet feeding motor 23 is stopped by the main control unit 18 The document is stopped after being driven for a minute, and the document is stopped at the reading position.

Here, the reading position is, for example, a position where the rear end position of the document in the conveying direction coincides with the front end of the left reference scale 56 which is the reference position of the contact glass 2. After the trailing edge of the document is detected, the distance is counted until the trailing edge of the document contacts the reference scale 56. Then, the document is exposed at this reading position by a known exposure unit including a light source, a mirror, a lens, a photosensitive drum and the like provided below the contact glass 2.

The paper discharging means 7 is provided with a reversing guide 71 which extends upward from the driven roller 52 on the contact glass 2 in a curved manner.
And a reversing / discharge motor provided along this guide 71.
The ADF 1 is provided on the downstream side of the reversing drive roller 73 and the sheet discharge drive roller 75 operated by the
A guide roller 74 rotatably supported by the main body and a document provided downstream of the guide roller 74 and conveyed by the reversing drive roller 73 are directly discharged to the document discharge section 6 by the discharge drive roller 75. After switching the first switching position and the upper and lower surfaces of the original, the original is switched to the second switching position for returning the original to the contact glass 2 via the turn passage 77 while holding the original by the inversion driving roller 73 and the inversion exit driven roller 76. And a possible switching claw 78.

The reversing / discharging motor 72 is driven by the main controller 18 and a timing belt 79 is provided.
And is connected to the driven pulley 80 via The driven pulley 80 is connected to a pulley 82 via a rotating shaft 81, and the pulley 82 transmits a driving force from a motor 72 to pulleys 84 and 85 via a timing belt 83. The pulley 84 is connected to a paper discharge roller 75 via a rotation shaft 86, and the pulley 85 is connected to a reversal drive roller 73 via a rotation shaft 87. The driving force from the reversing / discharge motor 72 is transmitted via each member.

On the other hand, the switching claw 78 is connected to a reversing solenoid 89 via a driving shaft 88, and the reversing solenoid 89 is driven ON / OFF by the main control unit 18. When the reversing solenoid 89 is turned off, the switching pawl 78 is switched to the first switching position by pulling the drive shaft 88 in the direction of arrow B by the return spring 90. Is discharged to The reversing solenoid 89 is turned on in the double-sided mode based on an output signal from the main control unit 18. At this time, the drive shaft 88 is pulled in the direction of arrow A against the pulling force of the return spring 90. As a result, the switching pawl 78 is switched to the second switching position, and the original is returned to the contact glass 2.

A paper discharge sensor 104 is provided between the reversing drive roller 73 and the guide roller 74. The paper discharge sensor 104 detects a document and outputs this detection information to the main control unit 18. ing. The main control unit 18 drives the reversing solenoid 89 based on the detection information to change the document discharge position. Meanwhile, the separation belt
20 constitutes a part of the separation belt unit 110 as shown in FIGS. That is, the separation belt unit 11
Reference numeral 0 denotes a bracket 111 which forms a part of the document reversing path and houses the separation belt 20 therein, and a separation belt 20 provided at the upper and lower ends of the bracket 111.
, And a separation belt drive roller 22 and a separation belt driven roller 112 wound around the roller.

A pair of notches 113 are provided at the upper end. A rod 114 is provided in the notch 113, and a spring 115 is inserted into the rod 114. Further, in the notch 113, a separation belt driven roller 112 is provided.
The driven shaft 116 rotatably supports the driven shaft 116. The driven shaft 116 is urged by a spring 115 to press the separation belt 20 via the driven roller 112. Therefore, a constant tension is applied to the separation belt 20.

The lower end of the bracket 111 is engaged with the separation belt driving roller 22, and the bracket 111 can swing about the separation belt driving roller 22 as a fulcrum. The separation belt driving roller 22 is slidably attached to the main body bracket 120 via a bearing 22a. Therefore, when a document jam occurs, the separation belt 20 is
The document can be removed from the contact surface between the separation belt 20 and the separation roller 19 at a distance from the document 19.

An original pressing plate 118 is provided on the bracket 111, and both ends of the original pressing plate 118 are movably engaged with the upper end of the bracket 111. Also,
The document holding plate 118 is disposed upstream of the separation roller 19 in the document transport direction, and separates the fed document bundle from the separation belt.
The guide is directed toward the contact surface between the separation roller 20 and the separation roller 19.

A flexible member 119 having a low coefficient of friction is fixed to the original pressing plate 118.
Reference numeral 19 is movable with the document holding plate 118, and its moving range is set between a position where the leading end enters the contact surface between the separation roller 19 and the separation belt 20 and a position where it retracts from the contact surface. I have. Next, a method of transporting a document by the ADF 1 will be described based on the flowcharts shown in FIGS. This flowchart shows a program stored in the ROM of the main control unit 18 and executed by the CPU 18a, and shows a process of conveying a document to the contact glass 2.

In the present embodiment, the mounting position of the flexible member 119 is set by a service person or the like before the document is conveyed. In other words, in the case of a user who frequently uses a thick paper document or a face curl document, the separation belt 20 is
Of the document holding plate
118 is moved along the bracket 111 to the downstream side in the document transport direction. When the separation belt 20 is swung in the direction of contact with the separation roller 19 with the separation roller drive roller 22 as a fulcrum, the tip of the flexible member 119 enters the contact surface between the separation roller 19 and the separation belt 20. Is set to the position where

In this state, in order to start the conveyance of the original, first, the original bundle is placed on the original placing table 3 so that the image side of the original faces upward, and the original is placed on the original stopper 8 at the entrance of the paper feeding unit. Set at the position where the tip abuts. The document bundle set to the position where it abuts the document stopper 8 lifts the detection filler 9 and determines whether or not the document set sensor 10 has detected that the document bundle has been set on the document table 3 ( Step S1), document set sensor 1
When 0 is turned on, it is determined whether or not a mode signal (whether a double-sided mode or a single-sided mode) is input (step S2).

Next, it is determined whether or not the mode signal is a one-sided mode signal (step S3). If the mode signal is determined to be a one-sided mode signal, whether the start switch is pressed in the mode set in the mode is determined. It is determined whether or not a paper feed signal has been input (step S
Four). On the other hand, when the signal is not the single-sided mode signal, it is determined that the mode is the double-sided mode, and it is determined whether or not the start switch is pressed in the state where the mode is set, that is, whether or not the sheet reversal signal is input. (Step S5).

When either the paper feed signal or the paper feed reversal signal is input in step S4 or step S5, the call solenoid 17 is turned on, and the paper feed motor 23 is driven to rotate clockwise in the forward direction. The motor 58 is driven to rotate forward in the counterclockwise direction, and the reversing / discharge motor 72 is driven to rotate forward in the counterclockwise direction. At this time, each motor 23, 58, 72
Starts a slow-up operation and counts the number of pulses of each motor (step S6).

That is, when the calling solenoid 17 is turned on, the rotating shaft 13 is rotated against the urging force of the spring 17b, the original stopper 8 moves upward from the original bundle S, and the pressing lever 12 moves the original bundle S. Is brought into contact with the call-out roller 11 via the contact roller 11, so that the document bundle is fed by the call-out roller 11 and conveyed between the separation roller 19 and the separation belt 20. At this time, since the separation belt 20 is stopped because the gear 32 is restricted from being rotated counterclockwise by the one-way clutch, the separation belt 20 is moved to the lowermost position of the original bundle by frictional separation by the separation roller 19 and the separation belt 20. The located document is separated, and only this document is conveyed by the separation roller 19, the pull-out drive roller 21, and the pull-out driven roller 21a.

Further, the leading end of the document bundle is guided by a document pressing plate 118 and a flexible member 119 to separate the separation roller 19 and the separation belt 2.
As described above, the lowermost document is smoothly separated by smoothly entering the contact surface of No. 0, and no non-feeding of the document occurs. At this time, the main controller 18 inputs a four-phase signal to the motor driver with a gradually shortened pulse width, thereby gradually shortening the pulse width when the coil is excited by the motor driver to feed the paper. The motor 23 is started by slow-up.

Then, it is determined whether or not the slow-up of each of the motors 23 and 58 has been completed since the separation of the document was started (step S7).
It is determined whether or not the leading edge of the document has been detected based on the detection information from the registration sensor 100 (step S8). If the registration sensor 100 is not ON, it is determined whether or not the pulse count of the paper feed motor 23 has reached the set value A (step S9). The set value A is set on the document table 3
This is the number of pulses obtained by adding the jam detection allowance distance to the distance from the leading end of the document set above to the registration sensor 100. Therefore, if it is determined in step S9 that the registration sensor 100 has not been turned on and the number of pulses of the paper feed motor 23 has reached the pulse count A, it is determined that a jam has occurred and jam processing is performed.

In this jam processing, after the motors 23, 58, 72 are slowed down, all the motors 23, 58, 72 are stopped. Usually, in this state, the user performs an operation of removing the jammed paper from the ADF 1. Therefore, it is determined whether or not the jammed paper is released based on the detection information from the registration sensor 100 and the width detection sensor 102, and the jammed paper is released. When it is determined that the processing has been completed, the processing of FIG. 7 is executed from the start.

On the other hand, if it is determined in step S8 that the registration sensor 100 has been turned on, the sheet feeding motor 23 and the conveying belt motor 58 are started at a slow speed (step S10). In order to start the paper feed motor 23 at a slowdown, the main controller 18 inputs a four-phase signal to the motor driver with a gradually increasing pulse width so that the pulse generated when the coil is excited by the motor driver is output. By gradually increasing the width, the feed motor 23 is started at a slow speed.

Next, it is determined whether or not the slowdown start of the sheet feeding motor 23 and the conveying belt motor 58 has been completed (step S11), and if so, the driving of the sheet feeding motor 23 and the conveying belt motor 58 is stopped. After that (step S12), as shown in FIG. 2, the sheet feeding motor 23 is driven to rotate in the counterclockwise direction, and the conveyor belt motor 58 is driven to rotate in the counterclockwise direction.
Are counted (step S13).

At this time, the rotation of the gear 33 by the one-way clutch is restricted by the reverse rotation drive of the paper feed motor 23, the call roller 11 and the separation roller 19 are stopped, and only the pull-out drive roller 21 rotates counterclockwise. I do. Also, the one-way clutch in the gear 32 is disengaged and the separation belt driving roller 22 is rotated, and the separation belt 20 stopped at the time of separation rotates clockwise, that is, in the direction opposite to the document conveyance, so that the retrieving roller is rotated. 11. By stopping the separation roller 19 and rotating the separation belt 20, the next document is prevented from entering the separation contact surface, and the document separated and conveyed first is pulled out by the pull-out driving roller 21, the driven roller 21a, and the conveyance motor 58.
The rotation of the conveyor belt 53 in the counterclockwise direction by the drive of
It is conveyed from the separation / conveyance means 4 to the conveyance means 5.

Next, it is determined whether or not the slow-up of the motors 23 and 58 has been completed (step S14). If the slow-up has been completed, it is determined whether or not the sensor 100 has been turned off based on the detection information from the registration sensor 100. That is, it is determined whether or not the trailing edge of the separated document has been detected (step S15). If the registration sensor has not been turned off, it is determined whether or not the number of pulses of the paper feed motor 23 has reached the set value C. It is determined (step S16). The set value C is set to a length obtained by adding the jam detection allowance distance to the maximum original length in the feeding direction. If the number of pulses of the paper feed motor 23 has reached the set value C while the registration sensor is OFF in step S16, the above-described jam processing is executed. In step S15, the registration sensor
If it is determined that 100 has been turned off, feed motor 2
Turn off 3 to release belt 20 and pull-out drive roller 2
When 1 is stopped and only the conveyance belt motor 58 is driven to convey the document onto the contact glass 2 (step S17), it is determined whether or not the single-sided non-collision mode is set (step S18).

If it is determined in step S18 that the single-sided non-collision mode is set, it is determined whether or not the pulse count value of the conveyor belt motor 58 has reached the pulse set value B.
The set value B is a value obtained by subtracting the distance required for slowing down the sheet feeding motor 23 and the transport belt motor 58 from the distance from the registration sensor 100 to the document stop position (the position where the rear end of the document contacts the reference scale 56). Is set.

If it is determined in step S19 that the pulse count value of the conveyor belt motor 58 has reached the set value B, the sheet feed motor 23 and the conveyor belt motor 58 are started slow down (step S20). Paper feed motor 23
Then, it is determined whether or not the slowdown of the transport belt motor 58 has been completed (step S21). When it is determined that the slowdown has been completed, the driving of the paper feed motor 23 and the transport belt motor 58 is stopped (step S22). ). Therefore, the original is exposed while the original is stopped at the original reading position on the contact glass 2. The description of the processing after step S22 is omitted.

For a user who frequently uses a thin paper document or a back-curled document, the separation belt 20 is swung in a direction away from the separation roller 19 with the separation belt driving roller 22 as a fulcrum, and the document pressing plate is moved. 118 is moved along the bracket 111 to the upstream side in the document transport direction. This movement position moves the separation belt 20 with the separation belt drive roller 22 as a fulcrum.
The tip of the flexible member 119 is set at a position where the tip of the flexible member 119 is retracted from the contact surface between the separation roller 19 and the separation belt 20 when the flexible member 119 is swung in the direction of contact with the separation roller 19.

When document transport is started in this state, the document bundle is separated by the above-described operation, but at this time, the leading edge of the document bundle is abutted against the separation belt 20 and double feed of the document occurs. There is no. Thus, in this embodiment,
Since the tip of the flexible member 119 can be freely moved between a position where it enters the contact surface between the separation roller 19 and the separation belt 20 and a position where it is retracted from this contact surface, the flexible member 119 is flexible when separating a thick paper document or a face curl document. By causing the tip of the member 119 to enter the contact surface between the separation roller 19 and the separation belt 20, the tip of the document bundle can smoothly and reliably enter the contact surface between the separation roller 19 and the separation belt 20. It is possible to prevent occurrence of non-feeding.

When separating a thin paper document or a back-curled document, the leading end of the flexible member 119 is retracted from the contact surface between the separating roller 19 and the separating belt 20, so that the leading end of the bundle of originals can be easily abutted against the separating belt 20. As a result, it is possible to prevent double feeding of originals. As a result, it is possible to stably separate many types of documents, and to improve the performance of separating documents.

The flexible member 119 is fixed to a document holding plate 118 for guiding a sheet bundle to be fed to the contact surface between the separation roller 19 and the separation belt 20, and the document holding plate 118 is fixed to the flexible member 119. Is supported by the bracket 119 so as to be located on the upstream side in the document conveying direction with respect to the original, so that a tall (thick) document bundle is contacted between the separation roller 19 and the separation belt 20 by the document pressing plate 118. You can be guided smoothly.

Since both ends of the document holding plate 118 are engaged with the bracket 111, the document holding plate 118 is
, The tip of the flexible member 119 can be moved between a position where it enters the contact surface between the separation roller 19 and the separation belt 20 and a position where it retracts from this contact surface. In the present embodiment, both ends of the document pressing plate 118 are engaged with the bracket 111. However, the present invention is not limited to this, and may be configured as shown in FIG.

That is, as shown in FIG.
A long hole 121 extending on both sides in the document conveying direction
a, a bolt (fixing member) 122 is inserted through the elongated hole 121a of the bracket 111, and fixes the pressing plate 121 to the bracket 111. When the flexible member 119 moves, the bolt 122 is loosened to release the original pressing plate. The document pressing plate 121 may be fixed to the bracket 111 by bolts 122 when the movement is completed by moving the 121 along the bracket 111. Even in this case, the tip of the flexible member 119 can be moved between the position where it enters the contact surface between the separation roller 19 and the separation belt 20 and the position where it retracts from this contact surface.

[0059]

According to the first aspect of the present invention, at the time of separating a thick paper document or a face curl document, the leading end of the flexible member is caused to enter the contact surface between the separating roller and the separating belt to thereby reduce the leading end of the document bundle. It is possible to smoothly and reliably enter the contact surface between the separation roller and the separation belt, and it is possible to prevent non-feeding of the document from occurring.

When a thin paper document or a back-curled document is separated, the leading end of the flexible member is retracted from the contact surface between the separating roller and the separating belt, so that the leading end of the bundle of documents can be easily abutted against the separating belt, so that the original can be separated. Double feed can be prevented from occurring. As a result, it is possible to stably separate many types of documents, and to improve the performance of separating documents.

According to the second aspect of the present invention, since the document holding plate is provided, a high (thick) document bundle can be smoothly guided to the contact surface between the separation roller and the separation belt by the document holding plate. Can be. According to the third or fourth aspect of the invention, by moving the document pressing plate with respect to the bracket, the leading end of the flexible member enters the contact surface between the separation roller and the separation belt and retracts from the contact surface. Can be moved to and from positions.

[Brief description of the drawings]

FIG. 1 is a schematic view of an embodiment of an automatic document feeder according to the present invention.

FIG. 2 is a schematic diagram of a drive mechanism of the automatic document feeder according to the embodiment.

FIG. 3 is a perspective view of a separation belt unit according to one embodiment.

FIG. 4 is an exploded view of a main part of the separation belt unit of one embodiment.

FIG. 5 is a configuration diagram of a bracket, a document pressing plate, and a flexible member of the separation belt unit of one embodiment.

FIG. 6 is a flowchart illustrating a document conveying procedure according to the embodiment.

FIG. 7 is a flowchart illustrating a procedure for conveying a document subsequent to FIG. 6;

FIG. 8 is a configuration diagram illustrating another mode of the bracket, the document pressing plate, and the flexible member of the separation belt unit according to the embodiment.

[Explanation of symbols]

 1 ADF (Automatic Document Feeder) 2 Contact Glass (Reading Position) 19 Separation Roller 20 Separation Belt 110 Separation Belt Unit 111 Bracket 118, 121 Document Holder 119 Flexible Member 121a Long Hole 122 Bolt (Fixed Member)

Claims (4)

[Claims] An automatic document feeder configured to separate a fed bundle of documents one by one by a separation roller and a separation belt unit and to convey the sheet bundle to a reading position, wherein the separation belt unit includes the separation roller. A separation belt that contacts the separation belt, a bracket that supports the separation belt so as to be able to move around, and a flexible member that is supported by the bracket and that guides a bundle of documents to be fed to the contact surface between the separation roller and the separation belt. An automatic document feeder, wherein the tip of the flexible member is movable between a position where it enters a contact surface between the separation roller and the separation belt and a position where it retracts from the contact surface. . 2. The flexible member is fixed to a document pressing plate that guides a bundle of documents to be fed to a contact surface between a separation roller and a separation belt, and the document pressing plate is configured to move the original to the flexible member. 2. The automatic document feeder according to claim 1, wherein the automatic document feeder is movably supported by the bracket so as to be located on the upstream side in the transport direction. 3. The automatic document feeder according to claim 2, wherein both ends of said document pressing plate are engaged with brackets. And a fixing member which is formed in the document pressing plate and extends in the direction of transport of the document, and which is inserted into the bracket and fixes the document pressing plate to the bracket. 3. The automatic document feeder according to claim 2, wherein: