JPH11217126A - Automatic manuscript carrying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To vary the slide-contact angle of a paper feed belt mechanically and change a separation pressure by the tension of the paper feed belt by varying the press position of the paper feed belt through a support member by a press position varying member. SOLUTION: By rotating a lever by a hand-powered device and a worm wheel through a worm gear and swinging the tip of a press member 80 by making a shaft to a swing fulcrum and varying the press position of the press member 80, a bracket 73 is swung by making a fixed shaft 71a to a fulcrum and the slide angle of the paper feed belt 11 is varied and the separation pressure by the tenion of the paper feed belt 11 is changed. Meantime, when the paper feed belt 11 is moved to a reverse roller 12 side, the separation pressure by the paper feed belt 11 can be set high and when the paper feed belt 11 is moved to a direction separated from the reverse roller 12, the separation pressure by the paper feed belt 11 can be set small.

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 provided in a copying machine, a facsimile machine, a scanner, and the like, and more particularly, to an endless sheet feeder for separating and feeding a stack of documents placed on a document table. And an automatic document feeder having a separation belt and a separation prevention member.

[0002]

2. Description of the Related Art In an automatic document feeder mounted on a copying machine, a facsimile machine, or a scanner, a document bundle placed on a document table can be separated and fed to be conveyed. In some cases, an endless feed belt and a separation preventing roller are used for the separation and feeding.

FIG. 10 shows an example of a conventional separating means having such a sheet feeding belt and a separation preventing roller. In FIG. 10, reference numeral 101 denotes a paper feed belt that can move in the document feeding direction.
Is in sliding contact with the separation preventing roller 102 which rotates in the document separation preventing direction. The paper feed belt 102 is wound around a driving roller 103 and a driven roller 104, and the driving roller 103 and the driven roller 104 are rotatably supported by a belt bracket 105. Although only one side surface of the belt bracket 105 is shown, the bracket 105 is formed in a substantially U-shape, and the other side surface is provided on the back side of the one side surface shown in the drawing.

The drive roller 103 is rotatably supported by a roller shaft 103a, and the roller shaft 103a is fixed to the main body of the automatic document feeder. The belt bracket 105 swings around the roller shaft 103a so that the sheet feeding belt 101 can contact and separate from the separation preventing roller 102. Notches 105a are formed on both sides of the belt bracket 105.
A is provided with a rod 106 (only one shown), and a compression spring 107 is provided on the rod 106. The compression spring 107 is provided between the bottom of the notch 105 a and the driven roller 10.
4, and urges the belt bracket 105 toward the drive roller 103 to apply a constant tension to the paper feed belt 101.

[0005] A pickup bracket 108 is provided outside the belt bracket 105, and the pickup bracket 108 can swing about a roller shaft 103a. A pickup roller 109 is rotatably mounted on the bracket 108, and the pickup roller 109 is attached to a document bundle P placed on a document tray 110.
Can be contacted by its own weight.

In the separating means having such a configuration, a predetermined tension is applied to the paper feeding belt 101 by the compression spring 107, and the paper feeding belt 101 is slidably contacted with the separation preventing roller 102 at a predetermined angle. Thus, the separation pressure of the document is applied. When the original bundle P on the original tray 110 is fed by the pickup roller 109, the uppermost document is separated by the feed belt 101 and the separation preventing roller 102, and then the document is transported to the feed belt 101. The original is conveyed onto the contact glass by a pull-out roller (not shown) provided on the downstream side in the direction.

[0007]

However, in such a conventional separating means, a tension is applied to the paper feed belt 101 by a compression spring 107 so that the separation pressure of the paper feed belt 101 is set. Had become
It is not possible to change the document separation pressure according to the type of document (thick paper document, thin paper document, size, etc.).

If the separation pressure is to be changed, the compression spring 107 must be changed, so that there has been a problem that the separation pressure can be changed stepwise and only at a large value. In order to change the separation pressure in this way, the compression spring 107 must be changed, which makes the operation of changing the separation pressure extremely troublesome, and is not practical.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an automatic document feeder capable of easily changing a separation pressure of a paper feed belt and setting an optimum separation pressure according to the type of a document. And

[0010]

According to the first aspect of the present invention,
In order to solve the above-mentioned problem, an endless paper feed belt provided with separation means for separating a document bundle, which is provided with initial tension, and moves around so as to convey the document in the paper feed direction, An automatic document feeder that has a separation preventing member that slides on the paper feeding belt at a predetermined angle and rotates in a document separation preventing direction, and separates the document by a separation pressure due to the tension of the paper feeding belt. A support member for swingably supporting the other end of the paper feed belt with one end of the belt as a fulcrum, and a separation preventing member for separating the paper feed belt via the support member with one end of the paper feed belt as a fulcrum An urging member for urging the paper feeding belt in a direction away from the paper feeding belt, and pressing the paper feed belt against the urging force of the urging member via the support member with the one end of the paper feed belt as a fulcrum. Holding member to be attached and the holding portion And a pressing position variable member that changes the pressing position of the paper feeding belt via the supporting member, and the pressing position of the paper feeding belt is changed via the supporting member by the pressing position variable member. Thereby, the sliding pressure of the paper feed belt is varied to change the separation pressure due to the tension of the paper feed belt.

In this case, the pressing position of the sheet feeding belt is changed by the pressing position variable member via the supporting member, so that the sliding contact angle of the sheet feeding belt is mechanically changed, and the separation pressure due to the tension of the sheet feeding belt is changed. Can be changed, the separation pressure of the paper feed belt can be easily changed, and the optimum separation pressure can be set according to the type of the document. According to a second aspect of the present invention, in order to solve the above-mentioned problem, in the first aspect of the present invention, there is provided input means for inputting a variable amount with respect to an initial position of the sheet feeding belt, and the pressing position variable member includes: The pressing member is driven based on the variable amount input from the input means.

In this case, the separation pressure due to the tension of the paper feeding belt can be changed based on the variable amount input by the operator, and the separation pressure of the paper feeding belt can be freely set from outside. According to a third aspect of the present invention, in order to solve the above-mentioned problem, in the first or second aspect of the present invention, the document separated by the separating means is moved to a reading position downstream of the separating means in the document conveying direction. The pressing position variable member is configured to change the pressing position of the pressing member when the document separated by the separating unit is transferred by the conveying member. The separation angle due to the tension of the paper feed belt is reduced by changing the sliding contact angle of the paper feed belt.

This is because if the tension of the paper feed belt remains constant when the original is separated by the paper feed belt and the separation preventing member and when the original is conveyed by the conveying member, the original is When the document is conveyed by the conveyance member, the surface of the document becomes dirty due to rubbing between the document surface and the paper feed belt or the separation preventing member, and when the subsequent document enters the nip portion of the paper feed belt or the separation preventing member, the originals are separated from each other. This is to prevent the document surface from being stained by rubbing.

That is, when the document is conveyed by the conveyance member, the separation pressure due to the tension of the paper feed belt is reduced, so that when the document is conveyed by the conveyance member, the document is reduced by the paper feed belt to the separation preventing member. Due to the pressure contact, the document surface can be prevented from being stained by the friction between the document surface and the feed belt or the separation preventing member, and the following document can enter the nip portion of the feed belt or the separation preventing member. Since the originals do not strongly contact each other when they are touched, it is possible to prevent the originals from being stained due to the rubbing between the originals.

According to a fourth aspect of the present invention, in order to solve the above-mentioned problems, in the first aspect of the present invention,
A sheet feeding member that feeds a bundle of documents placed on a document table to the sheet feeding belt and the separation preventing member, on the upstream side in the document conveying direction with respect to the sheet feeding belt and the separation preventing member, The paper supply member has a support bracket that swingably supports the paper supply member so as to be in contact with and separate from the original bundle, and the support bracket has the support member and one end of the paper supply belt as a fulcrum. When the paper feed belt is urged in a direction to separate from the separation preventing member, the paper supply belt is configured to be pressed by the support member and move in a direction to separate from the document bundle. When the document separated by is transported by the transport member,
By varying the holding position of the holding member and moving the supporting member in a direction away from the separation preventing member, the supporting bracket is pressed by the supporting member to separate the sheet feeding member from the document bundle. Features.

In this case, when the document is conveyed by the conveying member, the supporting bracket is pressed by the supporting member to separate the sheet feeding member from the document bundle, so that the subsequent document is not fed by the sheet feeding member. Can be Since the subsequent document is not fed by pressing the support bracket with the support member, it is not necessary to drive the paper feed member by a dedicated mechanism, and a mechanism for driving the paper feed member The number of parts can be reduced, and the configuration can be simplified.

According to a fifth aspect of the present invention, in order to solve the above-mentioned problems, in the first aspect of the present invention,
In a separation mode for separating a bundle of documents composed of a plurality of documents, the pressing position of the pressing member is changed by the pressing position variable member, so that the sliding contact angle of the sheet feeding belt via the support member can be set to the initial position or the input position. In the feed mode in which one sheet is fed by setting the position to the position input by the means, the pressing position of the pressing member is changed by the pressing position variable member, so that the feed belt is The sliding angle is varied from the initial position or the position input by the input means to reduce the separation pressure due to the tension of the sheet feeding belt.

In this case, in the separation mode for separating the document bundle composed of a plurality of documents, the sliding contact angle of the paper feed belt is set to the initial position or the position input by the input means, and the document is separated at an arbitrary separation pressure. Is performed, the document can be reliably separated. In the paper feed mode for feeding one document, the sliding contact angle of the paper feed belt is changed from the initial position or the position input by the input means to reduce the separation pressure due to the tension of the paper feed belt. In addition, it is possible to prevent the cut and pasted original from being peeled off and to protect the original, and also possible to prevent the original from being stained.

According to a sixth aspect of the present invention, in order to solve the above-mentioned problems, in the first to fifth aspects of the present invention, a mode input in which a variable amount with respect to an initial position of the sheet feeding belt is previously input as a plurality of modes Means for driving the holding member based on the variable amount input from the mode input means.

In this case, the variable amount with respect to the initial position of the sheet feeding belt is set in advance as a plurality of modes.
The separation pressure can be easily set from outside according to the type of the document. As the plurality of modes, dedicated switches are provided as switches of the operation unit such as “thin paper original”, “thick original”, “A4 original”, “B5 original”, and the like.
It can be configured with a dedicated switch, such as "260 g", "240 g", or "220 g", which indicates the separation pressure by a numeral.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 to 6 are views showing a first embodiment of an automatic document feeder according to the present invention, and correspond to the first aspect of the present invention. In this embodiment, an example in which the automatic document feeder is mounted on a copying machine is shown. However, the present invention can be applied to a facsimile machine, a scanner, and the like, in addition to the copying machine.

First, the configuration will be described. 1 and 2, reference numeral 1 denotes a copying machine, and a contact glass 2 constituting a reading position is provided on an upper surface of the copying machine 1. An automatic document feeder (hereinafter, simply referred to as an ADF) 3 is provided above the copying machine 1. The ADF 3 opens and closes the contact glass 2 so as to open and close the contact glass 2.
Are connected via a hinge (not shown) or the like.

The ADF 3 includes a document tray 4 as a document table on which a document bundle P including a plurality of documents can be placed;
After separating the originals one by one from the original bundle placed on the original tray 4, the separated originals are conveyed toward the contact glass 2, and the separated originals are fed to the contact glass 2 by the separated paper supply 5. The original conveyed toward and toward the reading position on the contact glass 2 is conveyed and stopped, and reading means (a well-known exposure lamp, mirror, lens, CCD, etc.) of the copying machine 1 disposed below the contact glass 2 is used.
Etc.), the original that has been read by the contact glass 2
Loading / unloading means 6 for unloading the original from the reading position of the contact glass 2 by the loading / unloading means 6 and a first discharge tray 8 or a document tray 4 protruding from the side of the copier 1. Paper discharge means 7 for discharging paper to one of the second paper discharge trays 9 provided. The first paper discharge tray 8 may be provided so as to protrude from the side of the ADF 3.

The document tray 4 is provided with a bottom plate 4a on the front side in the document feeding direction, and the bottom plate 4a is vertically swingable about a fulcrum 4b. The separation sheet feeding means 5 includes a pickup roller (sheet feeding member) 10, an endless sheet feeding belt 11, a reverse roller (separation preventing member) 12, a pull-out driving roller (conveying member) 13, a pull-out driven roller (conveying member) 13a. , Bottom bracket 14, resist sensor
15a and a document detection sensor 15b.

The bottom plate bracket 14 is vertically swingable about a fulcrum 14a, and is driven upward by a bottom plate motor 50 to raise the bottom plate 4a. The pickup roller 10, the paper feed belt 11, the reverse roller 12, and the pull-out drive roller 13 are driven by a paper feed motor 51, and are connected to the paper feed motor 51 via a drive system such as a gear mechanism.

The paper feed motor 51 is driven by an output signal from a controller 52. When a paper feed start signal is input from the main controller 53 of the copying machine 1, the controller 52 turns on the paper feed motor 51. It is designed to drive forward and reverse. This controller 52 has a CPU (Ce
ntral Processing Unit), RAM (Random Access Memo)
ry), a ROM (Read Only Memory), and controls various components of the ADF 3 in accordance with a program stored in the ROM to execute various sequences.
The RAM constitutes a work area in which various control values are stored.

When the paper feed motor 51 is driven to rotate forward, the pick-up roller 10 rotates clockwise to feed the upper document from the document bundle P, and the paper feed belt 11 feeds the document. While rotating in the clockwise direction, the reverse roller 12 is rotated in the clockwise direction as the document separation preventing direction, and only the top document is separated from the document bundle P.
In the present embodiment, the paper feed belt 11 and the reverse roller 12 constitute a separating unit.

The separated document is sandwiched between a pull-out driving roller 13 rotating in a counterclockwise direction and a pull-out driven roller 13a rotating therewith, pulled out from the paper feeding belt 11 and the reverse roller 12 and directed toward the contact glass 2. Transported. When the leading edge of this document is detected by the registration sensor 15a, the controller 53
The paper feed motor 51 is driven to rotate in the reverse direction based on the output signal from a. At this time, the feed motor 51 and the pickup roller 10,
The pickup roller 10 is driven by a drive system interposed between the feed belt 11, the reverse roller 12, and the pull-out drive roller 13.
The feed belt 11 is stopped, the pull-out drive roller 13 is continuously rotated counterclockwise, and the reverse roller 12 is rotated.
Is continuously rotated clockwise to prevent the following document from entering the nip portion between the feed belt 11 and the reverse roller 12, so that the document is not separated.

The pickup roller 10 is connected to a drive shaft of a paper feed belt 11 via a belt (not shown). The drive force from the paper feed belt 11 is applied to the pickup roller 10 by driving a paper feed motor 51. It is transmitted via a belt. The pickup roller 10 is supported by a pickup bracket, which will be described later in detail, and is driven by a drive solenoid 49 so that the pickup roller 10 comes into contact with and separates from the original bundle P about one end of the paper feed belt. Has become.

An original detection sensor 15b is provided near the bottom plate 4a. The sensor 15b detects the presence or absence of an original and outputs a signal to the controller 52. A pair of curved guide plates 42a, 42 is provided between the paper feed belt 11, the reverse roller 12, and the contact glass 2.
b is provided, and the document separated by the feed belt 11 and the reverse roller 12
The upper and lower surfaces are inverted by 42a and 42b, and are conveyed toward the contact glass 2.

On the other hand, the loading / unloading means 6 includes a transport belt 16
A conveyor belt driving roller 17 and a conveyor belt driven roller 18 provided at both ends of the conveyor belt 16;
A plurality of pressure rollers 19 are provided inside 16 and press the conveyor belt 16 against the contact glass 2. The transport belt driving roller 17 is driven by a transport belt motor 54, and the transport belt motor
When the leading edge of the document is detected by the registration sensor 15a as described above, the document is contacted by driving the transport belt 16 via the driving roller 17 by performing normal rotation driving based on a signal from the controller 52. It is designed to be conveyed onto the glass 2.

The controller 52 is connected to the registration sensor 15
When a detects the trailing end of the document, the number of rotation pulses of the conveyance belt motor 54 from the detection time is counted, and when the rotation pulse reaches a predetermined value, the driving of the driving roller 17 is stopped to stop the conveyance belt 16. Is stopped, the document is stopped at the reading position on the contact glass 2. Also the controller
52, when the trailing end of the original is detected by the registration sensor 15a, the paper feed motor 51 is driven again to separate the subsequent original as described above and convey it toward the contact glass 2, and this original is registered. At the point of time when the detection is made by the sensor 15a, the paper feed motor 51 is stopped and the next original is put on standby.

When the original stops at the reading position of the contact glass 2, the copying machine 1 reads and exposes the original. When the reading and the exposure are completed, a signal is input from the copier 1 to the controller 52. When the signal is input, the controller 52 drives the transport belt motor 54 to rotate in the normal direction, and the original is contacted by the transport belt 16. It is carried out from the glass 2 to the paper discharging means 7.

The paper discharge means 7 includes a reverse drive roller 20, a paper discharge driven roller 21, a reverse guide roller 22, a reverse driven roller 23, a first switching claw 24, a second switching claw 25, a paper discharge driving roller 26, and a paper discharge. Follower roller 2
7, a reversing sensor 28 and a paper ejection sensor 29, the reversing drive roller 20, the reversing guide roller 22, and the paper ejection drive roller 26
Are driven by a paper discharge motor 55.
The first switching claw 24 is switched and driven by a first solenoid 56. When discharging a one-sided original, the contact glass 2 and the first discharge tray 8 communicate with each other to linearly discharge the one-sided original. In the home position (where the lower surface of the switching claw 24 forms a part of the document conveyance path) where the paper discharge path 43 is formed.

The controller 52 operates in the one-sided mode for transporting a normal one-sided original (the operation unit 58 provided in the copying machine 1).
Even if the single-sided mode is not specified, the initial setting is set to the single-sided mode), the first switching claw 24 is caused to wait at the home position without driving the first solenoid 56, and the reading and exposure of the original are performed. After the end, the paper discharge motor 55 is driven at the same time as the transport belt motor 54 is driven. For this reason, the document sandwiched between the reversing drive roller 20 and the discharge driven roller 21 is discharged straight to the first discharge tray 8 without turning the front and back surfaces.

On the other hand, the controller 52 drives the first solenoid 56 based on a signal from the main controller 53 to operate the first switching claw 24 when the double-side mode is designated by the operation unit 58 provided in the copying machine 1. While moving from the home position to a position where the contact glass 2 and the reversing path 30 communicate with each other (the upper surface of the switching claw 24 constitutes a part of the document conveying path as shown in FIG. 1), one side of a double-sided document is read After the completion of the exposure, the transport belt motor 54 is driven, and at the same time, the paper discharge motor 55 is driven.

For this reason, the document is guided to the reversing path 30 sandwiched between the reversing drive roller 20 and the discharge driven roller 21, and is conveyed toward the second switching claw 25 by the reversing guide roller 22. The second switching claw 25 is driven by a second solenoid 57. When the document whose one side has been read is carried out of the contact glass 2, the second switching claw 25 is moved to the second position.
A home position position for opening the reversing return path 31 provided between the reversing path 30 and the contact glass 2 without being driven by the solenoid 57 (the second switching claw as shown in FIG. 1)
25 is configured to be switched to a part of a document conveyance path).

For this reason, the original conveyed out of the contact glass 2 is conveyed to the reversing path 30 by the first switching claw 24, and is then reversed by the second switching claw 25 to the reversing return path 31. Reverse drive roller 20 and reverse driven roller
23 and returned to the contact glass 2. When the leading edge of the document is detected by the reversing sensor 28 provided on the reversing path 30, the controller 52
To rotate the conveyor belt 16 in the reverse direction,
When the rotation pulse of the transport belt motor 54 from the time when the leading edge of the original is detected by the reference 28 reaches a predetermined value, it is determined that the original has been transported to the reading position on the contact glass 2 and the transport belt motor 54 is stopped. Let it.

When the reading of the original and the exposure at the reading position are completed, a signal is input from the copying machine 1 to the controller 52. When the signal is input, the controller 52 drives the transport belt motor 54 to rotate in the normal direction. The first solenoid 56 is driven and the driving of the second solenoid 57 is stopped. The first switching claw 24 connects the contact glass 2 to the reversing path 30, and the second switching claw 25 connects the reversing return path 31 to the second reversing path 31. By communicating the paper discharge tray 9 (the upper part of the second switching claw 25 forms a part of the document transport path), the document delivered from the contact glass 2 is held between the reversing driving roller 20 and the reversing driven roller 21. After being conveyed and conveyed, the sheet is nipped by the sheet discharge drive roller 26 and the sheet discharge driven roller 27 and discharged onto the second sheet discharge tray 9.

The copying machine 1 and the ADF 3 are connected via interfaces 59 and 60, and a copy start signal and a restart signal from the main controller 53 of the copying machine 1 are sent to the controller 52 via the interfaces 59 and 60. ADF3
Is supplied with power from the copier 1. Next, the configuration of the separating means will be described with reference to FIGS. 3 and 4, one end of the feed belt 11 is wound around a driving roller 71, and the other end of the feed belt 11 is driven by a driven roller.
72 is wound around the paper feed belt 11 and the drive roller 71
It is designed to move around. The driving roller 71 is rotatably supported by a fixed shaft 71a fixed to the main body of the ADF 3, and the paper feed belt 11 is configured such that the driven roller 72 can swing about the fixed shaft 71 as a fulcrum.

The driving roller 71 and the driven roller 72 are accommodated in the inner peripheral portion of a belt bracket (support member) 74. The belt bracket 73 is formed in a substantially U-shape, and has arm portions on both sides. 73a and 73b are formed. Also,
The belt bracket 73 is supported by bearings 74 formed at both ends of a fixed shaft 71a. The bearing 74 (only one of which is shown in FIG. 3) serves as a fulcrum and a driven roller together with the paper feed belt 11.
The 72 side is swingable.

The arm portions 73a, 73 of the belt bracket 73
b is formed with a notch 75, a rod 76 is provided in the notch 75, and a compression spring 77
a and 77b are provided. This compression spring 77a,
Reference numeral 77b is interposed between the bottom of the notch 75 and the driving roller 71, and urges the belt bracket 73 toward the driving roller 71 to apply a constant tension to the sheet feeding belt 11. For this reason, the feed belt 11 is in sliding contact with the reverse roller 12 with a constant tension.

A pickup bracket 78 is provided outside the belt bracket 73, and the pickup bracket 78 can swing about a bearing 74 as a fulcrum. The pickup roller 78 is rotatably mounted on the pickup bracket 78. The pickup roller 10 moves upward with the bearing 74 as a fulcrum when the bracket 78 is driven by the drive solenoid 49, so that the original bundle When the drive solenoid 49 is released while being separated from P, the bearing 74 is used as a fulcrum to come in contact with the original bundle P.

On the other hand, a torsion coil spring (biasing member) 79 is wound around the fixed shaft 71a, and the coil spring 79 is interposed between the guide plate 42a and the belt bracket 73 around the fixed shaft 71a. ing. For this reason, the belt bracket 73 is mounted on the bearing 74 by the coil spring 79.
The fulcrum is used to raise the driven roller 72 to urge it in a direction away from the reverse roller 12.

An opening 78a is formed in the upper surface of the pickup bracket 78, and the tip of the pressing member 80 contacts the belt bracket 73 through the opening 78a. The pressing member 80 is fixed to a shaft 81 as shown in FIG. 5, and a worm wheel 82 is attached to one end of the shaft 81. A worm gear 83 meshes with the wheel 82, and the worm gear 83 is rotated by a lever 84.

The lever 84 is adapted to be rotated by manual operation. When the lever 84 rotates, the worm wheel 82 is rotated via the worm gear 83, so that the tip of the holding member 80 is pivoted about the shaft 81 as a swing fulcrum. The part is swung. The shaft 81, the warwheel 82, the worm gear 83, and the lever 84 constitute a pressing position variable member 85, and the pressing position of the pressing member 80 is changed by the pressing position variable member 85 (see FIGS. 4 and 6). By pressing the bracket 73 against the reverse roller 12 against the urging force of the coil spring 79, the sliding contact angle of the feed belt 11 can be varied to change the separation pressure due to the tension of the feed belt 11. ing.

Next, a method of transporting a document will be described.
In the present embodiment, since the method of separating the document is important, the description of the method of transporting the double-sided document is omitted, and only the method of transporting the single-sided document will be described. In this embodiment,
In advance, the lever 84 is rotated by manual operation, and the worm wheel 82 is rotated via the worm gear 83, whereby the tip of the holding member 80 is swung with the shaft 81 as a swinging fulcrum, and the holding position of the holding member 80 is adjusted. By changing the angle, the bracket 73 is swung about the fixed shaft 71a as a fulcrum, and the sliding contact angle of the paper feed belt 11 is changed to change the separation pressure due to the tension of the paper feed belt 11 (FIG. 4, 6).

At this time, as shown in FIG.
When 11 moves to the reverse roller 12, the separation pressure by the paper feed belt 11 can be set higher. As shown in FIG. 6, when the paper feed belt 11 moves in the direction away from the reverse roller 12,
The separation pressure by the paper feed belt 11 can be set small. When transporting a small document such as B5, the document bundle P is placed on the bottom plate 4a with the document surface facing upward, and the document surface is directed upward when transporting a document larger than A4. The document bundle P is placed over the bottom plate 4 a and the document tray 4.

In this state, when a document bundle P composed of a plurality of single-sided documents is placed on the document tray 4 and a start switch (not shown) of the copier 1 is pressed, the copier 1 is supplied to the ADF 3 via the interfaces 59 and 60. A paper start signal is input. At this time, the driving force of the driving solenoid 49 is released, and the pickup roller 10 descends by its own weight. When the bottom plate motor 50 is driven, the bottom plate bracket 14 is lifted, the bottom plate 4a is raised, and the bottom plate motor 50 is stopped at an appropriate position where the document bundle P can be fed from the uppermost position.

The determination of the proper position is made by lifting the pickup roller 10 on which the original bundle P lifted together with the bottom plate 4a is lowered by its own weight, and picking up the pickup roller 10
Is detected by a sensor (not shown). Next, the paper feed motor 51 is driven to rotate forward to rotate the pickup roller 10 clockwise to feed the upper document from the document bundle P. Further, the paper feed belt 11 and the reverse roller 12 are both turned clockwise. To separate only the top document from the document bundle P.

The separated document is sandwiched between a pull-out driving roller 13 rotating in a counterclockwise direction and a pull-out driven roller 13a rotating therewith, pulled out from the paper feed belt 11 and the reverse roller 12 and directed toward the contact glass 2. Transported. Next, when the registration sensor 15a detects the leading edge of the document, the controller 52 determines whether there is a next document based on a detection signal from the document detection sensor 15b. If there is a next original, the controller 52 drives the drive solenoid 49 to mount the pickup bracket 78 on the bearing 74.
And raise the pickup roller 10 with the original bundle P
And the paper feed motor 51 is driven to rotate in the reverse direction, and the transport belt motor 54 is driven to rotate in the forward direction.

At this time, the pickup roller 10 and the feed belt 11 are stopped by the driving system interposed between the feed motor 51 and the pickup roller 10, the feed belt 11, the reverse roller 12, and the pull-out drive roller 13. Pull-out drive roller
13 is continuously rotated in the counterclockwise direction and the reverse roller 12 is continuously rotated in the clockwise direction, thereby preventing a subsequent document from entering the nip portion between the feed belt 11 and the reverse roller 12. So that they are not separated.

When the registration sensor 15a detects the trailing edge of the document during this conveyance, the controller 52 counts the rotation pulses of the conveyance belt motor 54 from the time of the detection, and when the rotation pulse reaches a predetermined value, the controller 52 starts driving. The original is stopped at the reading position on the contact glass 2 by stopping the driving of the rollers 17 and stopping the transport belt 16. On the other hand, when the registration sensor 15a detects the trailing end of the original, the controller 52 drives the paper feed motor 51 again, separates the subsequent original as described above, and
When the original is detected by the registration sensor 15a, the paper feed motor 51 is stopped to wait for the next original in advance.

When the document stops at the reading position of the contact glass 2, the copying machine 1 reads and exposes the document. When the reading and the exposure are completed, a restart signal is input from the copying machine 1 to the controller 52 via the interfaces 59 and 60.
The original 54 is driven to rotate forward, and the original is conveyed from the contact glass 2 to the paper discharging means 7 by the conveyor belt 16.

At this time, since the first switching claw 24 is waiting at the home position, the controller 52 drives the transport belt motor 54 after the completion of the reading of the original and the exposure, and at the same time, drives the discharge motor 55. . Therefore, the document held between the reversing drive roller 20 and the discharge driven roller 21 is discharged straight to the first discharge tray 8 without turning over the front and back surfaces.

When a feed start signal for the next original is input, the driving of the drive solenoid 49 is stopped, the pickup roller 10 is brought into contact with the original bundle P by its own weight, and the paper feed motor 51 is driven again. The pickup roller 10, the paper feed belt 11 and the like are driven to separate the succeeding document as described above and conveyed toward the contact glass 2 to continue the above-described processing.

As described above, in the present embodiment, the feed belt is changed by the pressing position variable member 85 through the belt bracket 73.
By varying the holding position of the paper feed belt 11, the sliding pressure of the paper feed belt 11 can be changed mechanically by changing the sliding contact angle of the paper feed belt 11, so that the separation pressure of the paper feed belt 11 can be reduced. The separation pressure can be easily changed, and the optimum separation pressure can be set according to the type of the document. FIGS. 7 to 9 are diagrams showing a second embodiment of the automatic document feeder according to the present invention, and correspond to any one of the second to sixth aspects of the present invention. In addition,
The present embodiment is characterized in that the separation pressure of the sheet feeding belt can be automatically adjusted. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. The description will be made with reference to the drawings used.

7 to 9, a large-diameter pulley 91 is attached to one end of a shaft 81 to which a pressing member 80 is fixed. The pulley 91 is attached to an output shaft of a motor 93 via a belt 92. Connected to the small diameter pulley 93a. The motor 93 is driven based on an output signal from the controller 52. When the motor 93 is driven, a shaft 81 is rotated via a pulley 93a, a belt 92 and a pulley 91, and the shaft 81 is swung. The distal end portion of the holding member 80 swings as a fulcrum.

A filler 94 is provided at a predetermined position of the shaft 81, and the filler 94 is detected by a sensor 95. When the sensor 95 detects the filler 94, it outputs a signal to the controller 52. When the detection information is input, the controller 52 determines that the pressing member 80 is at the home position.

On the other hand, the operation unit 58 is provided with a switch for inputting a variable amount and a direction with respect to the initial position (home position) of the sheet feeding belt 11, and input information of this switch is output to the controller 52. . Controller 52
Drives the motor 93 in the forward or reverse direction from the home position based on this input information, and
The separation pressure of the sheet feeding belt 11 is adjusted by changing the pressing position of the belt bracket 73 by the above.

In this embodiment, the operating section 58 constitutes an input means, and the shaft 81, the pulleys 91 and 93a, the belt 92, the motor 93, the filler 94, and the sensor 95 serve as a pressing position variable member.
Make up 96. Further, in the present embodiment, when the document is nipped by the pull-out driving roller 13a and the driven roller 13a and the leading edge of the document is detected by the registration sensor 15a, the controller 52 controls the motor 93 based on the detection information from the sensor 15a. By driving and moving the tip end of the holding member 80 upward, the paper feed belt 11 is moved upward via the belt bracket 73, and at this time, the sliding contact angle of the paper feed belt 11 is changed. The separation pressure due to the tension of the feed belt 11 is reduced variably.

The operation unit 58 has a separation pressure of the paper feed belt 11 which is variable according to a separation mode (ADF mode) for separating a bundle of documents and a paper feed mode (SADF mode) for feeding one document. It is supposed to be. That is, ADF
In the mode, the pressing position of the pressing member 80 is adjusted, and the sliding contact angle of the sheet feeding belt 11 via the belt bracket 73 is set to the initial position or a position corresponding to the input amount input by the operation unit 58.

On the other hand, in the SADF mode, a SADF switch for notifying this state is provided on the operation unit 58. When the SADF switch is pressed, the controller 52 drives the motor 93 by a predetermined amount and presses the presser. The pressing position of the member 80 is adjusted to move the sheet feeding belt 11 upward through the belt bracket 73. At this time, the sliding contact angle of the paper feed belt 11 becomes larger than the initial position, and the separation pressure due to the tension of the paper feed belt 11 is reduced.

Next, the operation will be described. In this embodiment, the first point is that the separation pressure of the paper feed belt 11 is automatically adjusted.
Unlike the first embodiment, other operations are the same as those of the first embodiment, and only the operations that are different from the first embodiment will be described. In the present embodiment, when the power of the copier 1 is turned on,
The motor 93 is driven until the filler 94 is detected by the sensor 95, that is, until the pressing member 80 is at the home position, and the separation pressure of the paper feed belt 11 is set to the initial pressure.

Then, when the moving amount and the moving direction are inputted from the home position by the operation unit 58, the motor 93 is driven in the normal rotation direction or the reverse rotation direction, and the pressing position of the belt bracket 73 by the pressing member 80 is changed to supply. Paper belt
The separation pressure of 11 is adjusted. When the separation pressure of the paper feed belt 11 is not set, that is, when the operation unit 58 is not operated, the pressing member 80 is in the state of being at the home position.

In this state, when a document bundle P composed of a plurality of single-sided documents is placed on the document tray 4 and a start switch (not shown) of the copying machine 1 is depressed, power is supplied from the copying machine 1 to the ADF 3 via the interfaces 59 and 60. A paper start signal is input. At this time, the driving force of the driving solenoid 49 is released, and the pickup roller 10 descends by its own weight. When the bottom plate motor 50 is driven, the bottom plate bracket 14 is lifted, the bottom plate 4a is raised, and the bottom plate motor 50 is stopped at an appropriate position where the document bundle P can be fed from the uppermost position.

Next, the paper feed motor 51 is driven to rotate forward to rotate the pickup roller 10 clockwise to feed the upper layer original from the original bundle P. Further, the paper feed belt 11 and the reverse roller 12 Rotate both clockwise to rotate the original bundle P
From the top document only. When the leading edge of this document is detected by the registration sensor 15a, the controller
53 drives the sheet feeding motor 51 in the reverse direction based on the output signal from the registration sensor 15a. At this time, the pickup roller 10 and the feed belt 11 are stopped by the drive system interposed between the feed motor 51 and the pickup roller 10, the feed belt 11, the reverse roller 12, and the pull-out drive roller 13, and the pull-out drive roller is stopped. 13 is continuously rotated in the counterclockwise direction and the reverse roller 12 is continuously rotated in the clockwise direction, thereby preventing a subsequent document from entering the nip portion between the feed belt 11 and the reverse roller 12. So that they are not separated.

When the original is nipped by the pull-out driving roller 13 and the driven roller 13a and the leading edge of the original is detected by the registration sensor 15a, the motor 93 is driven to move the distal end of the pressing member 80 upward. The paper feed belt 11 is moved upward through the belt bracket 73. At this time, the sliding angle of the feed belt 11 is
The separation pressure due to the tension of 11 is reduced.

On the other hand, when one document is fed,
When the ADF switch is operated, the motor 93 is driven, the pressing position of the pressing member 80 from the home position is adjusted, and the feed belt 11 is moved upward through the belt bracket 73, and the sliding of the feed belt 11 is performed. The contact angle becomes larger than the initial position, and the separation pressure due to the tension of the paper feed belt 11 is reduced.

As described above, in the present embodiment, the sheet feeding belt 11
An operation unit 58 for inputting a variable amount with respect to the initial position of
Because the presser position variable member 96 drives the presser member 80 based on the variable amount input from the operation unit 58,
In addition to the same effects as in the first embodiment, the separation pressure due to the tension of the paper feeding belt 11 can be changed based on the variable amount input by the operator, and the separation pressure of the paper feeding belt 11 can be freely set from outside. Can be set to

The separation belt 11 and the reverse roller 12
By varying the pressing position of the pressing member 80 when the original separated by the pull-out driving roller 13 and the pull-out driven roller 13a is conveyed, the sliding contact angle of the paper feed belt 11 is changed via the belt bracket 73. Thus, the separation pressure due to the tension of the paper feed belt 11 is reduced.

This is because the tension of the feed belt 11 is reduced when the original is separated by the feed belt 11 and the reverse roller 12 and when the original is conveyed by the pull-out drive roller 13 and the pull-out driven roller 13a. If the original is kept constant, when the original is conveyed by the pull-out driving roller 13 and the pull-out driven roller 13a, the original surface becomes dirty due to the rubbing between the original surface and the paper feed belt 11, and the subsequent original is This is to prevent the surface of the original from being stained by friction between the originals when the original enters the nip portion of the reverse roller 12.

That is, when the document is conveyed by the pull-out driving roller 13 and the pull-out driven roller 13a, the separation pressure due to the tension of the feed belt 11 is reduced, so that the document is conveyed by the pull-out driving roller 13 and the pull-out driven roller 13a. When the original is contacted with the reverse roller 12 by the paper feed belt 11 with a small pressure at the time of the feeding, the original surface can be prevented from being stained by rubbing between the original surface and the paper feed belt 11, and the following original can be Paper feed belt
Since the documents do not strongly contact each other when they enter the nip portion between the reverse roller 11 and the reverse roller 12, it is possible to prevent the document surface from being stained due to the friction between the documents.

In the ADF mode, the pressing position of the pressing member 80 is changed so that the sliding contact angle of the feed belt 11 via the belt bracket 73 can be changed to the initial position or the operating section.
When the document is separated, set the slide contact angle of the paper feed belt 11 to an arbitrary position and separate the document with an arbitrary separation pressure to separate the document reliably. Can be.

In the SADF mode, the feeding belt
Feeding belt 11 by changing the sliding angle of 11 from any position
By reducing the separation pressure caused by the tension, it is possible to prevent the cut and pasted document from being peeled off and to protect it, and also to prevent the document from being stained. In the present embodiment, the variable amount with respect to the initial position of the paper feed belt 11 is input by the operation unit 58, but this input method may be changed to a mode. That is, the operation unit (mode input means) 58 is provided with a plurality of mode switches indicating a variable amount with respect to the initial position of the paper feed belt 11.

In this case, the operation unit 58 displays “thin paper original”,
Dedicated switches such as "thick paper original", "A4 original", "B5 original", etc., "260g", "240g", "220g"
This can be achieved by providing a dedicated switch, such as "g", which indicates the separation pressure by a numeral. And the upper part from this switch is the controller
Output to the controller 52, and the controller 52
The separation pressure of the paper feed belt 11 is adjusted by controlling the position of the holding member 80 by controlling the position of the holding member 96. This makes it possible to easily set the separation pressure from the outside according to the type of the document.

In the present embodiment, the pickup roller
Although the drive solenoid 49 is moved in the direction away from the original bundle P by the drive solenoid 49, the drive solenoid 49 may be omitted. That is, in the present embodiment, the belt bracket 73
A gap is formed between the bracket 73 and the upper surface of the pickup bracket 78. When the pressing member 80 presses the belt bracket 73 through the opening 78a of the pickup bracket 78, the belt bracket is formed between the bracket 73 and the upper surface of the bracket 78. Since the sliding position of the paper feed belt 11 is changed by changing the position where the 73 is pressed, the separation pressure due to the tension of the paper feed belt 11 is changed, so that the bracket 73 contacts the upper surface of the bracket 78. The bracket 78 may be lifted together with the pickup roller 10 and moved away from the original bundle P when moving further upward in contact therewith (see FIG. 9).

Then, the bracket 78 is attached to the pickup roller.
The timing at which the document is moved up and separated from the document bundle P is the same as the timing at which the leading edge of the document is detected by the registration sensor 15a, that is, the drive solenoid.
What is necessary is just to set the same timing as the timing which drives 15a. In this way, when a document is conveyed by the pull-out driving roller 13 and the pull-out driven roller 13a, the pickup bracket 78 is pressed by the belt bracket 73 to separate the pickup roller 10 from the document bundle P, thereby picking up the pickup roller. By means of 10, it is possible to prevent the subsequent document from being fed. Since the subsequent document is not fed by pressing the pickup bracket 78 with the belt bracket 73, it is not necessary to drive the pickup roller 10 by a dedicated mechanism such as the drive solenoid 49. In addition, the number of components of the mechanism for driving the pickup roller 10 can be reduced, and the configuration can be simplified.

In the first and second embodiments, the operation section 58 is provided on the copying machine 1 side, but may be provided on the ADF 3 side.

[0080]

According to the first aspect of the present invention, the sliding position of the paper feeding belt is mechanically varied by varying the pressing position of the paper feeding belt via the supporting member by the variable pressing position member. Since the separation pressure due to the tension of the paper feed belt can be changed, the separation pressure of the paper feed belt can be easily changed, and the optimum separation pressure can be set according to the type of the document.

According to the second aspect of the present invention, the separation pressure due to the tension of the paper feed belt can be changed based on the variable amount input by the operator, and the separation pressure of the paper feed belt can be freely adjusted from outside. Can be set. According to the third aspect of the invention, the separation pressure due to the tension of the paper feed belt is reduced when the document is transported by the transport member, so that the document is transported by the paper feed belt when the document is transported by the transport member. Since the separation prevention member is contacted with a small pressure, the surface of the document can be prevented from being stained by the friction between the document surface and the feed belt or the separation prevention member.
When the following documents enter the nip portion of the paper feed belt or the separation preventing member, the documents do not strongly contact each other, so that the surface of the document can be prevented from being stained due to friction between the documents.

According to the fourth aspect of the present invention, when a document is conveyed by the conveyance member, the support bracket is pressed by the support member to separate the sheet supply member from the document bundle, so that the sheet is supplied by the sheet supply member. Document to be fed can be prevented from being fed. Since the subsequent document is not fed by pressing the support bracket with the support member, it is not necessary to drive the paper feed member by a dedicated mechanism, and a mechanism for driving the paper feed member The number of parts can be reduced, and the configuration can be simplified.

According to the fifth aspect of the present invention, in the separation mode for separating the original bundle, the sliding angle of the paper feed belt is set to the initial position or the position input by the input means, and the original is set at an arbitrary separation pressure. By separating the document, the document can be reliably separated. In the paper feed mode for feeding one document, the sliding contact angle of the paper feed belt is changed from the initial position or the position input by the input means to reduce the separation pressure due to the tension of the paper feed belt. In addition, it is possible to prevent the cut and pasted original from being peeled off and to protect the original, and also possible to prevent the original from being stained.

According to the sixth aspect of the present invention, by setting the variable amount with respect to the initial position of the sheet feeding belt in advance in a plurality of modes, the separation pressure can be easily set from the outside according to the type of the document.

[Brief description of the drawings]

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

FIG. 2 is a block diagram of a control system according to the first embodiment.

FIG. 3 is an exploded perspective view of the separation sheet feeding unit of the first embodiment.

FIG. 4 is a side view of a main part of the separation sheet feeding means according to the first embodiment, showing a state in which a separation pressure by a sheet feeding belt is set.

FIG. 5 is a perspective view of a pressing position variable member according to the first embodiment.

FIG. 6 is a side view of a main part of the separation sheet feeding means of the first embodiment, showing a state in which the separation pressure by the sheet feeding belt is set smaller than that in FIG.

FIG. 7 is a view showing a second embodiment of the automatic document feeder according to the present invention, and is a perspective view of a pressing position variable member.

FIG. 8 is a block diagram of a control system according to a second embodiment.

FIG. 9 is a side view of a main part of a separation sheet feeding unit according to a second embodiment, showing a state where a pickup roller is separated from a document bundle.

FIG. 10 is a perspective view of a main part of a conventional separation sheet feeding unit.

[Explanation of symbols]

 2 Contact glass (reading position) 3 ADF (automatic document feeder) 4 Document tray (document mounting table) 10 Pickup roller (paper feed member) 11 Paper feed belt (separation means) 12 Reverse roller (separation prevention member, paper feed means) 13 Pull-out drive roller (transport member) 13a Pull-out driven roller (transport member) 58 Operation unit (input means, mode input means) 73 Belt bracket (support member) 78 Pick-up bracket (support bracket) 79 Torsion coil spring (biasing member) ) 80 Presser member 85 96 Presser position variable member

Claims (6)

[Claims] An endless paper feed belt to which an initial tension is applied and which moves around so as to convey the original in a paper feeding direction; A separation preventing member that slides on the belt at a predetermined angle and rotates in the document separation preventing direction, and separates the document by separation pressure due to tension of the paper feeding belt; A support member that pivotally supports the other end of the paper feed belt with the portion as a fulcrum, and separates the paper feed belt from the separation preventing member via the support member with the one end of the paper feed belt as a fulcrum. An urging member for urging in a direction, and a pressing member for pressing the paper feeding belt against the separation preventing member against the urging force of the urging member via the supporting member with one end of the paper feeding belt as a fulcrum. And driving the holding member A pressing position variable member that changes a pressing position of the paper feeding belt via the support member, and the pressing position of the paper feeding belt is changed via the supporting member by the pressing position variable member, An automatic document feeder wherein the separation pressure due to the tension of the paper feed belt is changed by changing the sliding contact angle of the paper feed belt. 2. An input means for inputting a variable amount with respect to an initial position of the sheet feeding belt, wherein the pressing position variable member comprises:
2. The automatic document feeder according to claim 1, wherein the pressing member is driven based on a variable amount input from the input unit. 3. A transport member for transporting a document separated by the separating means toward a reading position downstream of the separating means in the document transport direction, wherein the pressing position variable member is separated by the separating means. By changing the pressing position of the pressing member when the fed document is conveyed by the conveying member, the sliding contact angle of the feeding belt is changed via the supporting member, and the separation pressure due to the tension of the feeding belt is changed. The automatic document feeder according to claim 1, wherein the number of images is reduced. 4. A sheet feeding member for feeding a bundle of documents placed on a document table to the sheet feeding belt and the separation preventing member on the upstream side in the document conveying direction with respect to the sheet feeding belt and the separation preventing member. The paper supply member has a support bracket that swingably supports the paper supply member so as to contact and separate the document bundle, and the support bracket supports one end of the paper supply belt as a fulcrum. When the support member and the paper feed belt are urged in a direction to separate from the separation preventing member, the support member is configured to be pressed by the support member and move in a direction to separate from the document bundle, When the document separated by the separation unit is conveyed by the conveyance member, by changing the pressing position of the pressing member to move the support member in a direction away from the separation preventing member, Automatic document feeder according to any one of claims 1 to 3 by pressing the supporting bracket in the support member, characterized in that to separating the said feed member from the document bundle. 5. In a separation mode for separating a document bundle composed of a plurality of documents, the pressing position of the pressing member is changed by the pressing position variable member, so that the sliding contact angle of the sheet feeding belt via the support member is adjusted. By setting the initial position or the position input by the input means, and in the paper feed mode for feeding one document, the pressing position of the pressing member is changed by the pressing position variable member, so that The separation pressure due to the tension of the paper feeding belt is reduced by changing the sliding contact angle of the paper feeding belt from the initial position or the position input by the input means. Automatic document feeder. 6. A mode input means for inputting a variable amount with respect to an initial position of the sheet feeding belt as a plurality of modes in advance, wherein the holding position variable member is configured to control the variable amount based on the variable amount input from the mode input means. The automatic document feeder according to any one of claims 1 to 5, wherein the presser member is driven by a press.