JPH09226970A - Automatic document transportation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent wrinkles to be generated in the end part of a document by providing at least two compression rollers compressing an endless transporta tion belt toward a contact glass and a first and a second fixed rollers allowed only to be rotated. SOLUTION: The generation of deflection in a transportation belt 53 can be restrained and a space defined among a standard scale 56, a contact glass 2, and the transportation belt 53 can be made small, because besides pressurizing the transportation belt 53 with a fixed roller 91, the transportation belt 53 is also pressurized with a fixed roller 92 disposed at the middle position between the fixed roller 91 and a compression roller 55. Therefore, when an end of a document bumps against an end of the standard scale 56, the generation of the bending in the end part of the document is prevented, so that the document can be prevented from being floated from the contact glass 2. Consequently, the generation of wrinkle in the end part of the document can be prevented and also the exposure of the deflected image of the document can be prevented.

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 mounted on an image forming apparatus such as a copying machine, a facsimile machine, and a compound facsimile machine. More specifically, the separated original document is projected onto a reference scale of contact glass. The present invention relates to an automatic document feeder having an endless conveyor belt that can be applied.

[0002]

2. Description of the Related Art Generally, an automatic document feeder (hereinafter referred to as an AD) provided in an image forming apparatus such as a copying machine, a facsimile machine, and a composite facsimile machine.
(Referred to as “F”) is to separate the originals placed on the original placing table one by one, convey the originals to the exposure position of the contact glass, expose the originals at this exposure position, and then discharge the originals onto the original output tray. It has become.

An endless rubber belt or a cloth rubber-coated belt (hereinafter referred to as a conveyor belt) has been used as a means for conveying the original to the contact glass. The reason for using such a conveyor belt is that the structure can be greatly simplified and the maintenance at the time of service is advantageous as compared with the case where an original is conveyed by a plurality of rollers.

A document conveyed to the contact glass by such a conveyance belt needs to be always conveyed and stopped at a fixed position in order to improve the exposure accuracy. Conventionally, an exposure reference position is set at the end of the contact glass. The following reference scale is provided, and the original is once conveyed on the contact glass by the conveyor belt, and then the conveyor belt is driven in reverse to abut the edge of the original against the reference scale to prevent the skew of the original.

By the way, according to such an abutting method, in the case of a document having a sufficiently strong strain, when the document strikes the reference scale, the skew of the document is corrected by the strain of the document itself. When a thin original is conveyed, the edge of the original may bend when it strikes the reference scale, and the original may float from the contact glass. If exposure is performed in this state, the original will bend on a straight line,
The problem that an image is optically bent and output occurs. In order to eliminate such a problem, it is necessary to prevent the original from rising from the contact glass by pressing the entire original evenly on the contact glass.

The structure will be described below with reference to FIGS. In FIGS. 18 and 19, reference numeral 301 is a reference scale provided at the end of the contact glass 302, and the end of the document is abutted against the reference scale 301. A drive roller 304 is provided at one end of the endless conveyor belt 303 provided so as to cover the contact glass 302 (the other end is not shown) (a driven roller is provided at the other end). Provided), the conveyor belt 303 is driven by this drive roller 304. Further, on the contact glass 302, a plurality of pressure rollers 305 arranged in a direction orthogonal to the moving direction of the conveyor belt 303 (only one shown).
The pressure rollers 305 are provided so as to be separated from each other in the moving direction of the transport belt 303 (the document transport direction), and press the transport belt 303 toward the contact glass 302.

A fixed roller 306 is arranged between the driving roller 304 and the pressure roller 305, and the fixed roller 306 faces the reference scale 301. For this reason, the conveyor belt 3
03 is brought into contact with the reference scale 301 by the fixed roller 306, and a gap is formed at the contact point between the conveyor belt 303 and the fixed roller 306 so that the conveyor belt 303 does not come into contact with the contact glass 302. The space defined between 302 and the conveyor belt 303 is made as small as possible. As a result, the document switched back by the conveyor belt 303 on the contact glass 302 is abutted against the reference scale 301 to secure the exposure reference position.

[0008]

However, in such a conventional automatic document feeder, the fixed roller 306 is used.
The conveyor belt 303 against the reference scale 301 by the fixed roller 306, thereby forming a small space between the reference scale 301, the contact glass 302 and the conveyor belt 303. If a rubber belt is used as 303,
As shown in 1, the conveyor belt 303 is bent between the fixed rollers 306.

For this reason, a large gap is created between the conveyor belt 303 and the contact glass 302, and when the end of the original is abutted against the reference scale 301, the end of the original is largely bent and the contact glass 302 is struck. Therefore, there is a problem in that the original is wrinkled and wrinkles are generated in the original, and the raised portion cannot be normally exposed, resulting in poor exposure of the original.

In order to eliminate such a problem, FIG.
As shown in FIG. 2, it is conceivable to use a cylindrical elastic member 307 such as a sponge. However, in this case, the contact resistance of the elastic member 307 with respect to the conveyor belt 303 increases, and the conveyor belt 303 is driven. The problem that an excessive load is applied to the drive motor that runs is caused. In addition to this, since the front surface of the elastic member 307 is in surface contact with the contact glass 302 or the reference scale 301, a considerable amount of static electricity is generated, and the document is stuck to the contact glass 302 or the transport belt 303 and the jam occurs. However, there was a problem that it became easier to do so, and it was not a good countermeasure.

Therefore, according to the present invention, the conveyance belt is prevented from being pressed and bent by the support member so that when the end of the document is abutted against the reference scale, the conveyance belt is bent and lifted from the contact glass. (EN) An automatic document feeder that can prevent the occurrence of wrinkles at the edges of a document and also prevent the image of the document from being exposed by bending. Has an aim.

[0012]

According to the first aspect of the present invention,
In order to solve the above-mentioned problems, an automatic document feeder that is provided so as to be openable and closable with respect to a contact glass on an image forming apparatus, wherein the documents are separated one by one from a document stack placed on a document table. Is conveyed to the exposure position on the contact glass, and the end of the document is abutted against the reference scale provided on the end of the contact glass,
In an automatic document feeder having a conveyance unit for preventing document skew, the conveyance unit is arranged in an endless conveyance belt provided to cover the contact glass and in a direction orthogonal to the document conveyance direction. Along with the contact glass, at least two or more pressing members that press the conveyor belt toward the contact glass are provided so as to be close to and away from each other, and are arranged in the direction orthogonal to the document conveying direction and via the conveyor belt. Between the pressing member and the first supporting member, which is provided to face the abutting surface of the reference scale and is rotatable only to press the conveyor belt toward the contact glass. A rotatable second support member that extends substantially parallel to the member and presses the conveyor belt toward the contact glass. There.

In this case, since the conveyor belt is pressed against the two support members, it is possible to prevent the conveyor belt from being bent when the conveyor belt is made of a rubber roller or the like. The space defined between the glass and the conveyor belt can be reduced.
Therefore, when the edge of the document is abutted against the reference scale, it is possible to prevent the edge of the document from being bent and to prevent the document from floating from the contact glass. As a result, it is possible to prevent wrinkles from being generated at the edges of the document, and it is possible to prevent the image of the document from being bent and exposed.

According to a second aspect of the present invention, in order to solve the above-mentioned problems, in the first aspect of the invention, the first and second support members are arranged in a direction orthogonal to a document conveying direction. It is characterized in that it has a plurality of rollers, and the rollers of the first and second support members are arranged at different levels. In that case, the contact surfaces of the first support member and the second support member and the conveyor belt form one plane,
When the conveyor belt is made of a rubber roller, it is possible to further suppress the occurrence of bending of the conveyor belt, and to further reduce the space defined between the reference scale, the contact glass and the conveyor belt, It is possible to further prevent wrinkles from being generated at the end portion of the document, and it is possible to further prevent the image of the document from being bent and exposed.

In order to solve the above-mentioned problems, the invention according to claim 3 is an automatic document feeder which is provided so as to be openable and closable with respect to a contact glass on an image forming apparatus, and is placed on a document table. Documents separated from the stack of originals are conveyed to the reading position on the contact glass,
In an automatic document feeder having a feeding unit for preventing the skew of an original by abutting the edge of the original against a reference scale provided on the edge of the contact glass,
The transport means is provided in an endless transport belt provided so as to cover the contact glass and in a direction orthogonal to the document transport direction, and is provided so as to be close to and separated from the contact glass, and the transport belt contacts the transport belt. And at least two pressing members that press against the glass; and a rotatable member that is provided between the reference scale and the pressing member and that presses the conveyor belt toward the contact glass. The support member has a rotating shaft extending in a direction orthogonal to the moving direction of the document, a plurality of first rollers that are fixed to the rotating shaft and press the document toward the contact glass, and a space between the first rollers. And a plurality of elastically deformable second rollers that are formed in a larger diameter than the first roller and that are closed by the device when the contact glass is closed. It is characterized in that presses against the conveyor belt the contact glass by elastic deformation.

In this case, when the main body of the apparatus closes the contact glass, the second roller elastically deforms and presses the edge of the document against the contact glass via the conveyor belt, so that the edge of the document is bent. Moreover, when the conveyor belt is formed of a rubber belt or the like, the conveyor belt is pressed by the first roller while forming a gap between the conveyor belt and the contact glass. Bending can be prevented from occurring. Further, it is possible to prevent an excessive load from being applied to the motor or the like that drives the conveyor belt due to the elastic deformation of the second roller.

Therefore, when the edge of the document is abutted against the reference scale, it is possible to prevent the edge of the document from bending and to prevent the document from rising from the contact glass. As a result, it is possible to prevent wrinkles from being generated at the edges of the document, and it is possible to prevent the image of the document from being bent and exposed.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 12 are views showing a first embodiment of an automatic document feeder according to the present invention and correspond to the invention described in claim 1 or 2. First, the configuration will be described. 1 and 2, reference numeral 1 is an automatic document feeder (hereinafter, simply referred to as A
DF), and the ADF1 is a copying machine not shown,
The contact glass 2 which is provided on the upper portion of an image forming apparatus such as a facsimile machine or a compound facsimile machine and constitutes a part of an exposure position is covered.

This ADF 1 separates and feeds a document placing table 3 on which a document bundle consisting of a plurality of documents can be placed, and the lowest document from the document stack on the document placing table 3 one by one. After that, the separating / conveying means 4 for conveying toward the contact glass 2, the conveying means 5 for conveying the document separated / conveyed by the separating / conveying means 4 to the original exposure position on the contact glass 2, and the contact glass 2. A sheet discharge means 7 having a sheet discharge path for discharging the above-exposed original document onto the original document discharge section 6 and a turn path for reversing the original document and returning it to the contact glass 2 again during double-sided original copy. ing.

The separating / conveying means 4 comes into contact with the leading end of the document stack when the document stack is set on the document mounting table 3 and prevents the document stack from entering inward.
An original set detection filler 9 that moves upward by coming into contact with the leading end of a bundle of originals set on the original placement table 3, and an original set sensor 10 that detects the detection filler 9 by separating from the detection filler 9. When the sensor 10 detects that the detection filler 9 is separated from the set sensor 10, it approaches the calling roller 11 and presses the original stack against the calling roller 11 to feed the original stack together with the calling roller 11.
12 and.

As shown in FIGS. 3 and 4, the document stopper 8 is fixed to a calling drive shaft 13, and a pressing lever 12 is fixed to the driving shaft 13 via a calling arm 14, and the pressing lever 12 is called the calling arm. It is rotatably connected to 14. A document stopper 8 is connected to the drive shaft 13 so as to be swingable relative to the drive shaft 13. The stopper 8 is restricted from moving in the thrust direction by an E-ring (not shown). Notches 8a and 9a are formed in the original stopper 8 and the filler 9, respectively.
The notches 8a and 9a are in contact with each other, and
Restricts rotation beyond rotation.

The drive shaft 13 is connected to a calling solenoid 17 as shown in FIG. 2, and the solenoid 17 is driven by a main controller 18. The main controller 18 is a CPU (Central Processing Uni
t), RAM (Random Access Memory), ROM (Read On
ly Memory) and the like, and executes the basic operation of the ADF 1.

The calling solenoid 17 has a rotating shaft 13 which is constantly urged by a spring 17b from a lever 17a.
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 composed of a keep solenoid, and the plunger once pulled is kept as it is due to the magnetic force of the keep solenoid.

Then, the calling solenoid 17 detects that the document set sensor 10 has set the document stack,
When a signal is output from the set sensor 10 to the main controller 18 and the start switch is pressed, the set sensor 10 is turned on based on the signal from the main controller 18 to rotate against the urging force of the spring 17b. The shaft 13 is rotated in the direction opposite to the predetermined direction to separate the document stopper 8 from the leading end of the document stack, and the pressing lever 12 is brought into contact with the calling roller 11 via the document stack.

Further, a compression spring 16 is interposed between the pressing lever 12 and the calling arm 14, and the pressing spring 12 causes the pressing lever 12 to call through a bundle of originals.
The original bundle is pressed with a sufficient pressing force when it comes into contact with the original bundle. Further, a pull-out driven roller 21a that is brought into contact with a separation roller 19, a separation belt 20, a pull-out roller 21, and a pull-out driving roller 21 by a spring (not shown) is provided downstream of the calling roller 11 in the document conveying direction. There is. The separation belt 20 is formed of an endless belt, and is driven by a separation belt driving roller 22. Then, the document bundle fed by the calling roller 11 is temporarily stopped between the separation roller 19 and the separation belt 20, and then the document at the lowest position is separated by the frictional force of the separation roller 19 and the separation belt 20. After that, the separation roller 19 and the pull-out roller 21 are conveyed toward the contact glass 2.

When the leading edge of the document stack 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 roller 21. The original is conveyed toward the contact glass 2. The calling roller 11, the separation roller 19, the separation belt 20, and the pull-out roller 21 described above are driven by a paper feed motor 23, which is a stepping motor, via a transmission mechanism 24.

That is, the driving force of the sheet feeding motor 23 is transmitted to the driven pulley 26 via the timing belt 25, and the driven pulley 26 transmits the driving force to the pulley 28 via the connecting shaft 27. It is supposed to do. The pulley 28 transmits a driving force to a pulley 30 via a timing belt 29. The pulley 30 transmits a driving force to gears 32 and 33 via a rotating shaft 31. gear
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. Also,
The gear 32 is connected to a gear 37 which can be rotated only in the counterclockwise direction by a one-way clutch via an idler gear 36. It is connected to the roller 21.

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

Therefore, when the paper feed motor 23 is rotated clockwise in FIG. 2, the calling roller 11, the separation roller 19 and the pullout drive roller 21 rotate counterclockwise with the separation belt 22 stopped. The stack of documents is fed and separated, and when the leading edge of the separated documents is detected by the registration sensor 100, the sheet feeding motor is instructed by the main controller 18.
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.

As shown in FIGS. 5 and 6, the conveying means 5 is composed of a conveying belt unit 200. The conveying belt unit 200 is rotatably attached to the main frame 201 mounted on the ADF 1 main body and the main frame 201. It is composed of an attached channel 202. The transport belt unit 200 is separated from the contact glass 2 in the document transport direction and is wound around the drive roller 51 and the driven roller 52, which are rotatably provided on the main frame 201 and the channel 202, respectively. Along with the main frame 201 and the channel 202, a rubber endless conveyor belt 53 (see FIG. 1) is rotatably provided on the main frame 201 between the conveyor belt 53 and the contact glass 2. A fixed roller (first supporting member) 91 and a fixed roller (second supporting member) 92 that determine the position of inserting the document into the main frame so that they are separated from each other by a predetermined distance in the extending direction of the contact glass 2.
Multiple rows of pressure rollers on 201 and channel 202
55 (four in this embodiment), the carrying means 5 carries the document to the exposure position by the carrying belt 53, and the exposed document is transferred from the contact glass 2 to the paper discharging means 7. It is something to be carried out. The pressure roller 55
There should be at least two or more.

In this embodiment, since the channel 202 is rotatably attached to the main frame 201, the channel 202 is rotated counterclockwise in FIG. The belt 53 can be easily attached and detached. The conveyor belt 53 is not limited to the rubber one, and may be composed of a member in which a cloth is rubber-coated. The conveyor belt unit 200 is not divided by the channel 202, and only the main frame 201 is provided. It may be an integrated type. The drive roller 51 may be on the driven roller 52 side.

The drive roller 51 is connected to a conveyor belt motor 58 via a transmission mechanism 57, and is driven by the conveyor belt motor 58. Conveyor 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 conveyor belt motor 58 to a pulley 62 attached to one end of the driving roller 51 via a timing belt 61. ing. 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 in the counterclockwise direction in FIG. 2 by the main controller 18 so as to convey the document together with the separation belt 20 and the pull-out driving roller 21 toward the document exposure position on the contact glass 2. When a signal indicating that the trailing edge of the document separated from the registration sensor 100 is input to the main control unit 18, the main control unit 18 stops the driving of the paper feed motor 23 and then the set number of pulses. After being driven for a minute, the document is stopped and the document is stopped at the exposure position.

Here, the exposure position is a position where, for example, the rear end position of the original in the conveyance direction coincides with the front end of the left reference scale 56 which is the reference position of the contact glass 2, and the above-mentioned setting pulse is set by the registration sensor 100. The distance until the trailing edge of the document comes into contact with the reference scale 56 after the trailing edge of the document is detected is counted. Then, the document is exposed at this exposure position by a known exposure means including a light source, a mirror, a lens, a photosensitive drum and the like provided below the contact glass 2.

On the other hand, the reference scale 56 is provided at the end of the contact glass 2, and the reference scale 56 is
As shown in FIG. 7, the recesses 56a and the protrusions 56 are alternately continuous.
Since the reference scale 56 has an end portion of the original document abutted against the reference scale 56, the exposure position of the original document is set while the skew and vertical registration of the original document are corrected.

Specifically, when the rear end of the original is detected by the registration sensor 100 when the original is conveyed toward the contact glass 2 by the separating / feeding means 4 and the conveying means 5, the main control section 18 is the registration sensor 100
From the time when the signal of
The number of rotations of 21a is counted, and when the counted number reaches a predetermined number, the conveyance belt motor 58 that drives the conveyance belt 53 is reversely driven to switch back the original on the contact glass 2 to thereby remove the original. Hit the reference scale 56.

When the exposure of the original is completed at the reading position of the contact glass 2 by the exposing means, the main controller 18 drives the conveyor belt motor 58 in the normal direction to convey the conveyor belt 53.
The original is carried out from the contact glass 2 toward the paper discharge means 7. On the other hand, the pressure roller 55 is
A roller row composed of a plurality of rollers 55b fixed to a rotation shaft 55a orthogonal to the document conveying direction (moving direction of the conveyor belt 53) is provided at intervals along the document conveying direction. Contact belt 2 with conveyor belt 53
It is adapted to apply a conveying force by pressurizing.

The pressure roller 55 is the contact glass 2
1, the main frame 201 and the channel 202 are mounted so as to be slidable in the vertical direction in FIG.
Pressure. Also, fixed rollers 91, 92
Has a plurality of rollers 91b and 92b fixed to rotating shafts 91a and 92a orthogonal to the document conveying direction.
Is attached to the main frame 201 so as to be rotatable only in the rotation direction.

Further, as shown in FIG. 8, the roller 91b of the fixed roller 91a is opposed to the abutting surface side of the reference scale 56 via the conveyor belt 53, and the outer peripheral end is slightly recessed into the recess 56a. Only the amount is inserted. Further, the fixed roller 92 is provided in the intermediate portion between the fixed roller 91 and the pressure roller 55 closest to the fixed roller 91, and both the rollers 91 and 92 are both the conveyor belt 53.
Is pressed toward the contact glass 2. Therefore, at the contact point between the fixed roller 91b and the conveyor belt 53, a constant gap can be provided between the conveyor belt 53 and the contact glass 2, so that the conveyor belt 53 abuts the convex portion 56b of the reference scale 56. You can The gap between the rollers 91 and 92 and the contact glass 2 is set to at least about 0.5 mm, which is at least the thickness of the conveyor belt 53.

The sheet discharging means 7 is a reversing guide 71 which is curved and extends upward from the driven roller 52 side on the contact glass 2.
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 that is rotatably supported by the main body 1a, and a document that is provided on the downstream side of the guide roller 74 and that is conveyed by the reversing drive roller 73 is discharged to the document discharge section 6 as it is by the discharge driving roller 75. To the second switching position where the upper and lower surfaces of the original are reversed and then the original is nipped by the reverse driving roller 73 and the reverse outlet driven roller 76 and returned to the contact glass 2 through the turn passage 77. And a switching claw 78 capable of switching.

The reversing / sheet discharging motor 72 is adapted to be driven by the main control section 18, and the timing belt 79
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 drive shaft 88, and the reversing solenoid 89 is ON / OFF driven by the main controller 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 101 is provided between the reverse driving roller 73 and the guide roller 74. The paper discharge sensor 101 detects a document and outputs this detection information to the main controller 18. ing. The main control unit 18 drives the reversing solenoid 89 based on the detection information to change the document discharge position. In addition, in FIG. 1, 10
Reference numeral 2 denotes a size detection sensor, and this sensor 102 detects the length of the document in the width direction and outputs document size information to the main control unit 18.

Next, the operation will be described. ADF of this embodiment
1 is capable of conveying both double-sided originals and single-sided originals, the present embodiment uses the fixed rollers 91, 92 for conveying belts.
Since there is a point in pressing 53 toward the contact glass 2, only a single-sided document conveyance will be described.

First, a document bundle having an image formed on one side is placed on the document placing table 3 so that the image surface of the document P faces upward, and the leading end of the document P strikes the document stopper 8 at the entrance of the paper feed section. Set to the position. The document bundle set up to the position where it abuts the document stopper 8 is detected by the detection filler 9
Then, the document set sensor 10 detects that the document stack is set on the document table 3, and the document set sensor 10 is turned on.

Next, when the start switch is pressed in the single-sided mode, the calling solenoid 17 is turned on, the paper feed motor 23 is driven clockwise in the clockwise direction, and the conveyor belt motor 58 is driven counterclockwise in the normal direction. To be done. That is,
When the call solenoid 17 is turned on, the rotary shaft 13 is rotated against the urging force of the spring 17b, the document stopper 8 moves upward from the document stack, and the pressing lever 12 moves to the call roller 11 via the document stack. Because of the contact state, the bundle of documents is fed by the calling roller 11 and conveyed between the separation roller 19 and the separation belt 20. At this time, the separation belt 20
Is stopped because the gear 32 is restricted from rotating in the counterclockwise direction by the one-way clutch, and the lowermost original P of the original stack is separated by friction separation by the separation roller 19 and the separation belt 20. Then, only the original P is conveyed by the separation roller 19, the pullout driving roller 20 and the pullout driven roller 20a.

Next, when the leading edge of the document P is detected based on the detection information from the registration sensor 100, the paper feed motor 23 is driven in the counterclockwise direction in reverse and the conveyor belt motor 58 is rotated in the counterclockwise direction. Drive to roll. By the reverse drive of the paper feed motor 23, the rotation of the gear 33 is restricted by the one-way clutch, the calling roller 11 and the separation roller 19 are stopped, and only the pull-out driving roller 21 rotates counterclockwise.

Further, the one-way clutch in the gear 32 is disengaged and the separation belt driving roller 22 is rotated, so that the separation belt 19 stopped at the time of separation is in the clockwise direction, that is, the original P.
Since it rotates in the opposite direction to the transport, the calling roller 11 and the separation roller
By stopping 19 and rotating the separation belt 20, the next original P is prevented from entering the separation nip portion, and the original P previously separated and conveyed is driven by the pull-out driving roller 21, the driven roller 21a, and the conveyance motor 58. By the counterclockwise rotation of the conveyor belt 53 by the
Transported to

Then, when the trailing edge of the separated original P is detected by the registration sensor 100, the encoder counts the number of rotations of the driven roller 21a from the time when the main control unit 18 detects the signal of the registration sensor 100. When the count number reaches a predetermined number, the conveyance belt motor 58 that drives the conveyance belt 53 is reversely driven to switch back the document P on the contact glass 2 to bring the document P against the reference scale 56. (A series of operations up to this point is shown in FIG. 9).

Next, when the original P is conveyed to the exposure position, the driving of the paper feed motor 23 and the conveyance belt motor 58 is stopped, and the original P is stopped at the exposure position on the contact glass 2 while the original surface is kept. To expose. When the exposure is completed, the conveyor belt motor 58 and the reversing / sheet discharging motor 72 are driven in the normal direction. At this time, the reversing solenoid 89 is off and the return spring 90 causes the drive shaft 88 to move to the arrow B
Since the switching claw 78 is switched to the first switching position by being pulled in the direction, the conveyor belt 53 and the guide roller 53
The original P conveyed by 74 or the like is ejected onto the original ejection unit 6 with the original surface facing upward, as in the state in which the original P was initially set on the original placing table 3.

In this embodiment, in addition to pressurizing the conveyor belt 53 by the fixed roller 91, the conveyor belt 53 is also pressurized by the stationary roller 92 provided at an intermediate position between the stationary roller 91 and the pressure roller 55. Therefore, it is possible to suppress the occurrence of bending of the conveyor belt 53, and it is possible to reduce the space defined between the reference scale 56, the contact glass 2 and the conveyor belt 53. Therefore, when the edge of the document is abutted against the edge of the reference scale 56, the contact glass 2 is prevented from bending at the edge of the document.
It is possible to prevent it from rising. As a result, it is possible to prevent wrinkles from being generated at the edges of the document, and it is possible to prevent the image of the document from being bent and exposed.

Further, in the present embodiment, it is possible to prevent the end portion of the document from being bent only by adding the fixed roller 92 to the fixed roller 91. As described above, it is possible to prevent the contact area with the contact glass from becoming large, and to minimize the transfer resistance of the transfer belt and the damage due to static electricity associated with the transfer. In the present embodiment, the fixed roller 91 and the fixed roller 92 are provided separately, but not limited to this, as shown in FIGS.
The distance between the axes of the rollers 91b and 92b is the same as that of the rollers 91b and 92.
Each roller 91b, 92b should be shorter than the total radius of b
May be arranged in different steps.

In this way, the contact surfaces of the fixed rollers 91, 91 and the conveyor belt 53 can be formed as one flat surface, and the occurrence of bending of the conveyor belt 53 can be further suppressed, and the above effect can be obtained. Can be obtained more reliably. Further, in the present embodiment, the reference scale 56 is arranged on the left side of the separating / feeding means 4 in FIG. 1, but the present invention is not limited to this.
As shown in FIG. 12, it may be arranged on the right side of the sheet discharging means 7 and the fixed rollers 91, 92 may be arranged on the side of the reference scale 56. However, in this case, as shown in the figure, switchback is not necessary, but in order to ensure that the end portion of the document is abutted against the reference scale 56 and a route for carrying out the document from the contact glass 2 is secured after exposure. In addition, it is necessary to provide means for retracting the reference scale 56 downward from the contact glass 2 and returning it to the abutting position of the document.

13 to 17 are views showing a second embodiment of the automatic document feeder according to the present invention, and correspond to the invention described in claim 3. The present embodiment is different from the first embodiment only in that the shape of the fixing roller is changed to one, and the other configurations are the same. Therefore, the same configurations are denoted by the same reference numerals. Is omitted.

13 and 14, a fixed roller (support member) 94 disposed between the reference scale 56 and the pressure roller 55 is a rotary shaft 95 rotatably attached to the main frame 201 only in the rotational direction. , A plurality of first rollers 96 which are fixed to the rotary shaft 95 and are made of hard rubber or plastic or the like and press the document toward the contact glass 2.
And is arranged between the first roller 96 and the first roller 96.
And a plurality of elastically deformable second rollers 97 formed of a soft member such as sponge and having a diameter larger than 96.

Each of these rollers 96 and 97 is a reference scale.
It faces the concave portion 56a of 56, and this concave portion 56a is
The cut diameter is set according to the width of 6, 97. In the fixed roller 94 having such a structure, when the ADF 1 is closed to the contact glass 2, the second roller 97
By elastically deforming and reducing the diameter, the contact glass 2 is pressed against the end portion of the original document via the conveyor belt 53, so that the end portion of the original document can be prevented from being bent. Further, since the first roller 96 presses the conveyor belt 53 toward the contact glass 2 while forming a gap between the conveyor belt 53 and the contact glass 2, it is possible to prevent the conveyor belt 53 from being bent. it can. Further, it is possible to prevent an excessive load from being applied to the conveyor belt motor 58 that drives the conveyor belt 53 due to the elastic deformation of the second roller 97.

As a result, when the edge of the original is abutted against the reference scale 56, it is possible to prevent the edge of the original from bending and prevent it from rising from the contact glass 2. It is possible to prevent wrinkles from being generated in the portion and to prevent the image of the original document from being bent and exposed. The pressing force applied by the second roller 97 can be elastically deformed by reducing the width of the first roller 97 as well as being set by selecting the material. Therefore, any material and width can be selected as long as the pressure can be set to the extent that an excessive load can be prevented from being applied to the conveyor belt motor 58.

As a method of arranging the first roller 96 and the second roller 97, when the document transport reference is the center reference,
As shown in FIG. 15 (a), the second roller 97 is arranged in the center, and when the document conveyance reference is the front or back end face reference in FIG. 1, the end face of the document is always the second roller 97. In order to hit the edge, the second roller 97 may be arranged at the end as shown in FIG. 15 (b). Note that FIG. 16 (a) is a diagram showing the relationship between the fixed roller 94 and the conveyor belt 53 when arranged as shown in FIG. 15 (a), and FIG. 16 (b) is as shown in FIG. 15 (b). FIG. 6 is a diagram showing a relationship between a fixed roller 94 and a conveyor belt 53 when they are arranged.

In addition, in the present embodiment, the second roller 97 is made of an elastic member such as sponge, but the present invention is not limited to this.
As shown in FIG. 17, the roller may be made of a material similar to that of the first roller 96 with an elastic member such as a sponge fitted on the outer peripheral portion of the roller. Can be obtained.

[0060]

According to the first aspect of the present invention, since the conveyor belt is pressed by the two supporting members, when the conveyor belt is made of a rubber roller or the like, it is possible to prevent the conveyor belt from bending. Can be a reference scale,
The space defined between the contact glass and the conveyor belt can be reduced. Therefore, when the edge of the document is abutted against the reference scale, it is possible to prevent the edge of the document from being bent and to prevent the document from floating from the contact glass. As a result, it is possible to prevent wrinkles from being generated at the edges of the document, and it is possible to prevent the image of the document from being bent and exposed.

According to the second aspect of the present invention, the contact surfaces of the first support member and the second support member and the conveyor belt can be formed as one plane, and when the conveyor belt is made of a rubber roller, the conveyor belt is conveyed. It is possible to further suppress the occurrence of bending of the belt, and to further reduce the space defined between the reference scale, the contact glass and the conveyor belt, and to prevent wrinkles from being generated at the edge of the document. It is possible to further prevent the image of the original from being bent and exposed.

According to the third aspect of the present invention, when the main body of the apparatus closes the contact glass, the second roller is elastically deformed to press the end portion of the original against the contact glass via the conveying belt. It is possible to prevent the occurrence of bending at the end of the conveyor belt, and when the conveyor belt is made of a rubber belt or the like, the conveyor belt is pressed by the first roller while forming a gap between the conveyor belt and the contact glass. Therefore, it is possible to prevent the conveyance belt from being bent. Further, it is possible to prevent an excessive load from being applied to the motor or the like that drives the conveyor belt due to the elastic deformation of the second roller.

Therefore, when the edge of the original is abutted against the reference scale, it is possible to prevent the edge of the original from bending and prevent it from rising from the contact glass. As a result, it is possible to prevent wrinkles from being generated at the edges of the document, and it is possible to prevent the image of the document from being bent and exposed.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a first 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 first embodiment.

FIG. 3 is a perspective view of a document stopper, a detection filler, a calling arm, and a calling roller that constitute a part of the separating / conveying means of the first embodiment.

4A is a side view of a calling arm and a presser lever of the first embodiment, FIG. 4B is a configuration diagram of a document stopper and a detection siller, and FIG. 4C is a rotation in which a detection filler detects a document bundle. It is a figure which shows the state which was done.

FIG. 5 is a configuration diagram of a transport unit according to the first embodiment.

FIG. 6 is a configuration diagram of the main parts of the transport unit according to the first embodiment.

FIG. 7 is a configuration diagram of a reference scale according to the first embodiment.

FIG. 8A is a diagram showing a positional relationship between a fixed roller and a pressure roller of the first embodiment, and FIG. 8B is a diagram showing a state where the conveyor belt is pressed by a pair of fixed rollers.

FIG. 9 is a diagram illustrating an operation from a document feeding to a switchback according to the first embodiment.

FIG. 10 is a main part configuration diagram of a transport unit showing another aspect of the fixed roller of the first embodiment.

FIG. 11 is a diagram showing a positional relationship between a fixed roller and a pressure roller showing another aspect of the first embodiment.

FIG. 12 is a diagram illustrating an operation of another mode from the document feeding to the switchback according to the first embodiment.

FIG. 13 is a side view of the main parts of the conveying means showing the second embodiment of the automatic document feeder according to the present invention.

FIG. 14 is a perspective view of a main part of a fixed roller according to a second embodiment.

FIG. 15A is a diagram showing a positional relationship between the first roller and the second roller when the document conveyance reference of the second embodiment is the center reference;
FIG. 6B is a diagram showing a positional relationship between the first roller and the second roller when the document conveyance reference is the front or back end face reference.

16 (a) is a first roller and a second roller as shown in FIG. 15 (a).
FIG. 16 is a diagram showing the relationship between the fixed roller and the conveyor belt when the rollers are provided, and FIG. 15B is the fixed roller and the conveyor belt when the first roller and the second roller are provided as shown in FIG. 15B. It is a figure which shows the relationship of.

FIG. 17 is a diagram showing another aspect of the stationary roller of the second embodiment.

FIG. 18 is a side view of a main part of a conventional conveying unit.

FIG. 19 is a perspective bottom view of a main part of a conventional conveying unit.

FIG. 20 is a side view showing a state in which the conveyor belt is bent by pressure applied by a conventional fixed roller.

FIG. 21 is a front view showing a state in which a conveyor belt is bent by pressure applied by a conventional fixed roller.

FIG. 22 is a perspective bottom view of a main part of a conventional conveying unit having a cylindrical fixed roller such as a sponge.

[Explanation of symbols]

 1 ADF (Automatic Document Feeder) 2 Contact Glass 5 Conveyor 53 Conveyor Belt 55 Pressure Roller (Pressure Member) 91 Fixed Roller (First Support Member) 91b Roller 92 Fixed Roller (Second Support Member) 92b Roller 94 Fixed Roller (support member) 95 Rotating shaft 96 1st roller 97 2nd roller

Claims (3)

[Claims] 1. An automatic document feeder, which is provided so as to be openable and closable with respect to a contact glass on an image forming apparatus, wherein the originals separated from a stack of originals placed on an original table are brought into contact glass. In the automatic document feeder, the document is conveyed to the upper exposure position, and the document is skewed by abutting the end of the document against a reference scale provided at the end of the contact glass. The means is arranged in an endless conveying belt provided so as to cover the contact glass, and is arranged in a direction orthogonal to the document conveying direction, and
At least 2 which are provided so as to be close to and apart from the contact glass and press the conveyor belt toward the contact glass.
One or more pressure members, which are arranged in a direction orthogonal to the document transport direction, are provided to face the abutting surface of the reference scale via the transport belt, and press the transport belt toward the contact glass. A rotatable first support member, and a rotatable only support member extending between the pressing member and the first support member substantially parallel to the first support member and pressing the conveyor belt toward the contact glass. An automatic document feeder having two supporting members. 2. The first and second supporting members have a plurality of rollers arranged in a direction orthogonal to a document conveying direction,
2. The automatic document feeder according to claim 1, wherein the rollers of the first and second support members are arranged at different levels. 3. An automatic document feeder, which is provided so as to be openable and closable with respect to a contact glass on an image forming apparatus, wherein the originals separated one by one from a bundle of originals placed on an original placing table are brought into contact glass. In the automatic document feeder, the document is conveyed to an upper reading position, and the document is skewed by abutting the end of the document against a reference scale provided at the end of the contact glass. The means is arranged in an endless conveying belt provided so as to cover the contact glass, and is arranged in a direction orthogonal to the document conveying direction, and
At least 2 which are provided so as to be close to and apart from the contact glass and press the conveyor belt toward the contact glass.
One or more pressure members, and a freely rotatable support member that is provided between the reference scale and the pressure member and presses the conveyor belt toward the contact glass. A rotating shaft extending in a direction orthogonal to the direction; a plurality of first rollers fixed to the rotating shaft to press the document toward the contact glass; and a first roller arranged between the first rollers. A plurality of elastically deformable second rollers formed to have a diameter larger than that of the rollers, and when the device closes the contact glass, the second rollers
An automatic document feeder, characterized in that a roller is elastically deformed to press the conveyor belt against a contact glass.