JP3494996B2 - Paper feeder and image recording apparatus having the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding apparatus capable of switching between upper separation for feeding stacked documents from the top and lower separation for feeding documents from the bottom, and more particularly to a facsimile. The present invention relates to a sheet feeding device of an image forming apparatus having both a function and a document copying function, and an image recording apparatus including the same.

[0002]

2. Description of the Related Art Conventionally, a facsimile apparatus and a copying machine are different in a method of feeding a document due to a difference in function or culture provided between them. In a copying machine, since the copy sheets are discharged onto the discharge tray of the post-processing device such as a sorter or finisher in the same order as the originals before being fed, it is necessary to feed the sheets from the last page of the stacked originals. is there. On the other hand, in the facsimile apparatus, since the original is transmitted from the first page, it is necessary to feed the original from the first page of the stacked originals.

In recent years, the demand for an image forming apparatus (hereinafter referred to as a "multifunction machine") having such a facsimile function and a copying function is expected to increase. In such a complex machine, both upper and lower separation sheet feeding functions are required.

As a sheet feeding device having the above-mentioned function, there is one disclosed in Japanese Patent Laid-Open No. 8-202088. In this Japanese Patent Laid-Open Publication No. 8-202088, rollers having a half-moon cross section are arranged on the upper side and the lower side of the original, respectively, and when performing upper separation feeding, the half-moon rollers arranged on the upper side of the original are independently provided. While rotating and feeding the uppermost original of the stacked originals, when performing lower separation feeding, the half-moon roller arranged below the originals is independently rotated to be stacked. The document at the bottom of the documents is being fed.

[0005]

However, in the above-described paper feeding device, the document is separated by bringing the peripheral surface of the half-moon roller into contact with the document to feed the document, and the document separating section is disposed in front of the document in the paper feeding direction. When the document arrives at, the contact between the half-moon roller and the document is eliminated to prevent the document from being fed too much. Therefore, the peripheral surface of the half-moon roller needs to have the same length as the distance for the document to reach the document separating portion when it comes into contact with the document.

Further, the half-moon roller must always be positioned at the home position where the plane portion of the half-moon roller faces the original before starting the feeding of the original. Therefore, it is necessary to perform control to return to the home position each time one original is fed. In this way, when feeding originals, a special half-moon roller mechanism is required,
There is also a problem that the control of the half-moon roller becomes complicated.

Further, in the above-mentioned paper feeding device, the position of the half-moon roller arranged above the document is fixed.
For this reason, the amount of originals that can be placed on the paper feeding device is limited. Therefore, when feeding a large number of originals,
There is a problem in workability because it requires the addition of manuscripts.

The present invention has been made in view of the above point, and enables both upper and lower separation and feeding of originals with a simple mechanism and control, and is excellent in workability. The purpose is to provide a device.

[0009]

SUMMARY OF THE INVENTION According to the present invention, a separating means is provided between a pair of separation rollers and a pair of pickup rollers to protrude from above into a conveying path to contact an original and separate the original, and the original is separated from a bundle of originals. When separating the uppermost original, the lower separating means is moved from below to the conveying path to prevent the lower part of the original bundle from being conveyed, while when separating the lowermost original from the original bundle, double feeding is prevented. By moving the means from above to the conveying path, the separating means first comes into contact with the originals to separate the originals, and thereafter, the upper portion of the original stack is prevented from being conveyed by the double feed preventing means.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A sheet feeding device according to a first aspect of the present invention is a pair of separating rollers for separating a bundle of originals one by one and a pair of separating rollers for feeding a bundle of originals from a document placing table to the pair of separating rollers. A pickup roller, a separating unit that protrudes from above between the pair of separation rollers and the pair of pickup rollers onto the conveying path to contact the document and separates the document, and a contact portion between the document bundle and the separation unit. And a lower separating means that moves from the lower side to the conveying path on the upstream side in the original conveying direction to prevent the lower part of the protruding document stack from being conveyed, and moves from the upper side to the conveying path on the downstream side of the contact portion in the original conveying direction. Double feed prevention means for preventing the upper part of the original document stack from being conveyed, and lower separation means for separating the uppermost document from the original document stack to prevent the lower part of the original document stack from being conveyed, while bundle When separating the Luo lowermost original by moving prevention means said heavy feed, said separating means is in contact with the document separating document first, followed by the double feed preventing means
Switching means for preventing the upper part of the document stack from being conveyed,
The configuration including is adopted.

According to this structure, when the uppermost original is separated from the original bundle, the lower separating means is moved from below to above the paper path to prevent the lower portion of the original bundle from being conveyed. Since the leading end of the document stack in which the uppermost original remains thin after passing through the lower separating means can be inclined by the separating means and supplied to the pair of separating rollers, on the other hand, the lowermost document from the original stack can be fed. When separating the originals, first, the separating means contacts the originals to separate the originals, and then the double feed preventing means prevents the upper portion of the original stack from being conveyed, so that the weight of the originals becomes larger than that during the upper separating operation. Even in the lower separation operation where it is difficult to feed a certain amount, the stack of originals with the thinnest remaining originals can be fed to the pair of separation rollers, so the originals can be separated by a simple configuration and control. Paper feed and bottom It is possible to enable both the release paper feeding.

In the sheet feeding device according to the second aspect of the present invention, in the first aspect, the lower pickup roller is moved to a position that covers the surface of the lower pickup roller of the pair of pickup rollers and the lowermost surface of the document stack is moved to the lower pickup roller. The second double feed preventing means is provided so as not to be in contact with the surface of the document, and the second double feed preventing means moves to the position when separating the uppermost document from the document stack.

With this configuration, it is possible to prevent the layers of a large number of originals from being supplied to the pair of separation rollers when the originals placed on the original placing table are few.

A paper feeding device according to a third aspect of the present invention is
In the second aspect, the second double feed preventing means is formed of a material having a smaller friction coefficient than the surface of the lower pickup roller and a larger friction coefficient than the original .

According to this structure, when only one original is placed on the original table, the original does not advance due to the frictional force of the lower pinch roller and the original is prevented from being fed. .

In the sheet feeding device according to the fourth aspect of the present invention, in the first aspect, the pickup pressure for the document stack placed on the document mounting table is for separating the lowest document from the document stack. This is larger than the case of separating the uppermost document from the document stack.

According to this structure, when the lowermost original is separated from the original bundle, the pickup pressure for the original can be made larger than when separating the uppermost original from the original bundle. It is possible to easily feed the original even when the lowest original is separated. Generally, a document is difficult to feed due to its own weight when separating the lowest document from a document stack. For this reason, in the present paper feeding device, when the lowest document is separated from the document stack, the pickup pressure is increased to facilitate feeding the document. Thus, even when the lowest document is separated from the document stack, the document can be easily fed.

A paper feeding device according to a fifth aspect of the present invention is
In a first aspect, on the separation roller of the pair of separation rollers, when separating the original top-level from the document bundle, it is rotated in the direction of conveying the document, in the case of separating the lowermost original from the original stack , Stop rotation when multiple documents are fed.
When the lowermost original is fed, the lower separating roller of the pair of separating rollers rotates around, and the lower separating roller separates the uppermost original from the original bundle . When multiple documents are fed, the document rotates in the direction opposite to the document transport direction, and only the top document is fed.
In this case, the upper separation roller is rotated along with the rotation of the upper separation roller, and when separating the lowest document from the document stack , it is rotated in the direction in which the document is conveyed.

According to this configuration, when separating the lowest document from the document stack, the upper separation roller is configured by a plurality of documents.
Since the rotation is stopped when the paper is fed , even if the separating means is protruding in the vicinity of the upper separating roller, it is possible to prevent the original from bending and entering between the upper separating roller and the separating means. it can.

An image recording apparatus according to a sixth aspect of the present invention is an image recording apparatus in which the sheet feeding device according to any one of claims 1 to 5 is applied. As described above, by applying the present invention to the image recording apparatus, the effect of the sheet feeding device according to the present invention can be obtained in the image recording apparatus.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic configuration diagram of a multi-function machine equipped with a sheet feeding device according to an embodiment of the present invention.

In FIG. 1, a multifunction peripheral 100 is an apparatus main body 1 in which components for forming an image on recording paper are housed.
01 and a sheet feeding device 102 provided on the apparatus main body 101 and capable of separating a stack of originals from above and below.

As shown in FIG. 2, this paper feeding device 102
Is a tray 2 for discharging the documents stacked on the document table 201.
Pickup rollers 203A and 203B, and separation rollers 204A and 204 for transferring to 02A and 202B.
B, a registration roller 205, a conveyance roller 206, and paper discharge rollers 207A and 207B. In the paper feeding device 102, various rollers are used to load the document on the document table 201.
The rotation when the sheet is conveyed in the direction from the discharge tray 202 is called normal rotation, and the opposite rotation is called reverse rotation. Further, in the paper feeding device 102, the documents stacked on the document table 201 are
The reading surface is on the lower side, and when there are multiple sheets, they are stacked with the first page at the bottom.

When a document is set in the paper feeding device 102, the document is in a state of slightly protruding from the front end of the document table 201 into the apparatus. The original placing table 2
The part of the document protruding from 01 is a lower pickup roller (hereinafter, referred to as “lower pickup roller”) 203.
A supports from below. The lower pickup roller 203A rotates in the normal direction during the lower separation sheet feeding and feeds the lowest document to the separation rollers 204A and 204B.

On the other hand, an upper pickup roller (hereinafter referred to as "upper pickup roller") 203B is provided at a position facing the lower pickup roller 203A with the original interposed therebetween.
Are arranged. This upper pickup roller 203B
Is configured to be able to move up and down. The upper pickup roller 203B moves to a position where it comes into contact with the uppermost document in the upper separating and feeding, and then rotates forward to feed the uppermost document to the separating rollers 204A and 204B.

These pick-up rollers 203A, 2
03B, a pair of separation rollers 20 at a certain distance
4A and 204B are arranged. The pair of separation rollers 204A and 204B is the pickup roller 203.
The original bundle fed from A and 203B in an overlapping state is separated into only one uppermost or lowermost original. That is, when the originals are fed in the overlapping state during the lower separation feeding, only the lowest original is separated, and the originals are fed in the overlapping state during the upper separating feeding. If it does, it separates only the top document.

An upper pickup roller 203B and an upper separation roller (hereinafter referred to as "upper separation roller") 204
B is connected by a roller bracket 208. The roller bracket 208 works to press the upper pickup roller 203B against the original in conjunction with the normal rotation of the upper separation roller 204B during the copying operation.

A registration roller 205 and a conveyance roller 2 arranged in front of the separation rollers 204A and 204B in the sheet feeding direction.
06, the first paper ejection roller 207A and the second paper ejection roller 2
Reference numeral 07B is a paper ejection tray 202B or a paper ejection tray 202 for the documents separated by the separation rollers 204A and 204B.
Transport to A. Conveyor roller 206 and first paper discharge roller 2
A paper discharge switching claw 209 is provided between the printer and 07A. By moving the position of the paper discharge switching claw 209, it is determined whether the paper is discharged to the first paper discharge roller 207A or the second paper discharge roller 207B. Book feeder 1
02, when performing copying, a paper discharge tray 202A
When the facsimile transmission is performed, the sheet is discharged to the discharge tray 202B.

An optical unit 103 is arranged above the apparatus main body 101 facing the paper feeding apparatus 102. The optical unit 103 is composed of an optical system for reading a document through a reading window provided on the document conveyance path, and a CCD for analyzing an image of the read document and converting it into an image signal. The optical unit 103 sends the image signal of the image read from the document to the LSU 104. LSU104
Forms a latent image of the received image signal on the drum 105.

On the other hand, a paper feed cassette 106 is arranged below the apparatus main body 101. This paper feed cassette 1
The uppermost recording sheet of the sheets stacked on the sheet 06 is taken out by the pickup roller 107. The recording paper taken out from the paper feed cassette 106 is separated by the separation roller 10
8, it is conveyed to the drum 105 via the conveyance roller 109 and the registration roller 110.

The developing unit 111 applies toner to the drum 1 in accordance with the latent image of the image signal formed on the drum 105.
Attach to 05. The transfer charger 112 includes the drum 105.
Transfer the toner adhering on the recording paper to the recording paper. The conveyance belt 113 uses the recording paper on which the toner is attached to the fixing unit 11.
Transport to 4. The fixing unit 114 includes a fixing roller and a pressure roller, and fixes the toner on the recording paper when the recording paper passes between them. The discharge roller 115 is
Eject the recording paper after toner fixing. When performing double-sided copying on recording paper, the recording paper is conveyed to the automatic double-sided system 116 without being ejected. The automatic double-sided system 116 conveys the recording paper upside down to the drum 105 again.

Next, the relationship between the pickup roller and the separation roller will be described with reference to FIG. FIG. 3 is a perspective view of a drive system from the motor to the separation roller and the pickup roller inside the paper feeding device 102.

As shown in FIG. 3, a pulley 302 and a connecting gear 303 provided at the tip of the drive shaft of the motor 301.
The pulley 304 integrally provided on the rotating shaft of the belt 30
5 are connected.

Two gears, an upper gear 306 and a lower gear 307, mesh with the connecting gear 303. The upper separation roller 204B is attached to the other end of the upper shaft 308 having the upper gear 306 fixed to one end. Further, a lower separation roller (hereinafter, referred to as “lower separation roller”) 204 is provided at the other end of the lower shaft 309 having the lower gear 307 fixed at one end.
A is attached.

A friction belt 204B-2 made of two rubber materials is wound around the upper separation roller 204B around the outer periphery of the roller base 204B-1 at a predetermined distance. The lower separation roller 204A has the same structure.

An upper pickup roller 203B is arranged in parallel with the upper separation roller 204B at a predetermined distance. The upper shaft 308 to which the upper separation roller 204B is attached and the shaft 310 to which the upper pickup roller 203B is attached are connected by a connecting member 311 and a roller bracket 208.

The connecting member 311 is pierced by the upper shaft 308 through a pair of axially opposed side walls. Connection member 3
One end of the shaft 310 is held by a bearing portion 311A formed to project from 11. On the other hand, roller bracket 208
Is the upper separation roller 204B and the upper pickup roller 20.
3B, and the upper shaft 3 from the opposite side of the connecting member 311.
08 and the tip of the shaft 310 are supported.

Further, the upper shaft 308 and the shaft 310 have:
Pulleys are mounted adjacent to the rollers. The pulley 312 on the upper shaft 308 side is attached to the upper shaft 308 via a one-way clutch. This one-way clutch transmits the rotational force of the upper shaft 308 to the pulley 312 when the upper shaft 308 rotates in the direction of arrow B in the drawing, and transmits the rotational force of the upper shaft 308 when the upper shaft 308 rotates in the direction of arrow A in the drawing. Not transmitted to the pulley 312.
As a result, when the upper shaft 308 rotates in the direction of arrow B in the figure, the pulley 312 rotates in the same direction, and the upper shaft 308 rotates.
Is rotated in the direction of arrow A in the figure, the pulley 312 is stopped. The pulley 313 on the shaft 310 side is attached to the shaft 310 via a one-way clutch, and
Roller base 203 of upper pickup roller 203B
It is fixed with respect to B-1. A belt 314 connects between these pulleys 312 and 313.

The lower separation roller 2 has the same positional relationship as the upper separation roller 204B and the upper pickup roller 203B.
04A and the lower pickup roller 203A are arranged in parallel.

The tip of the lower shaft 309 is attached to the paper feeding device 10.
The lower pickup roller 203A is rotatably supported by a part of the second housing, and the tip of the shaft 318 of the lower pickup roller 203A is attached to the paper feeding device 10.
It is fixed to a part of the housing of No. 2. Similar to the upper side, pulleys 315 and 316 are attached to the respective shafts adjacent to the rollers, respectively. Pulley 3 on the lower shaft 309 side
15 is attached to the lower shaft 309 via a one-way clutch.
When the lower shaft 309 rotates in the direction of arrow A in the figure, its rotational force is transmitted to the pulley 315, and when the lower shaft 309 rotates in the direction of arrow B, the rotational force of the lower shaft 309 is not transmitted to the pulley 315. . The pulley 316 on the lower pickup roller 203A side is the shaft 3 of the lower pickup roller 203A.
It is attached to 18 via a one-way clutch,
Moreover, it is fixed to the roller base of the lower pickup roller 203A. This one-way clutch is
When the pulley 316 rotates in the direction of arrow A in the drawing, it idles, and when it rotates in the direction of arrow B in the drawing, it is locked. Between both of these pulleys 315, 316, the belt 31
They are connected by 7.

Next, the relationship between the upper separation roller and the upper pickup roller will be described with reference to FIGS. 4 and 5. FIG. 4 is a perspective view showing the inside of the upper separation roller and the upper pickup roller. FIG. 5 is a sectional view taken along the solid line A in FIG.

In FIG. 4, the upper shaft 308 penetrates the central portion of the roller base 204B-1. Upper shaft 3
The tip of 08 is rotatably supported by a boss 208A provided at one end of the roller bracket 208. A one-way clutch 401 is attached to the outer circumference of the boss 208A. The one-way clutch 401 is press-fitted into an opening at one end of the roller base 204B-1 and is integrated with the roller base 204B-1. By the action of the one-way clutch 401,
When the roller base 204B-1 rotates in the direction of arrow B in FIG. 4, the roller base 204B-1 is locked to the boss 208A of the roller bracket 208, and the rotation of the roller base 204B-1 is stopped.

On the other hand, a torque limiter is fitted on the upper shaft 308 at the other end of the roller base 204B-1. The torque limiter is composed of a fixed boss 402, a limiter boss 403, and a limiter spring 404. The fixed boss 402 is integrally fixed to the roller base 204B-1. The limiter boss 403 is fixed to the upper shaft 308 by a parallel pin 405.

The limiter spring 404 is wound around the fixed boss 402 and the limiter boss 403. As shown in FIG. 4, one end of the limiter spring 404 on the side of the fixed boss 402 is bent into an L shape, and the tip end of the L shape is inserted into a groove provided in the fixed boss 402. . As a result, the fixed boss 402 and the limiter spring 404 move integrally. On the other hand, the other end of the limiter spring 404 is tightened by the limiter boss 403. As a result, when the rotation of the roller base 204B-1 is not restricted by the one-way clutch 401 or the like, the rotation of the limiter boss 403 is transmitted to the fixed boss 402 via the limiter spring 404.

On the other hand, when the rotation of the roller base 204B-1 is restricted by the frictional force between the one-way clutch 401 or the upper separation roller 204B and the document,
The limiter spring 404 slides between the limiter boss 403 and the upper shaft 308 rotates independently of the roller base 204B-1. This torque limiter is also incorporated in the lower separation roller 204A.

Next, the state before the paper feeding operation in this paper feeding apparatus will be described with reference to FIG. FIG. 6 shows a state in which upper separation feeding of the present feeding device is performed.

As shown in FIG. 6, a shaft 601 is rotatably supported by the housing of the paper feeding device 102 in parallel with the upper shaft 308 by a predetermined distance. The first arm 60 is attached to the shaft 601.
One end of 2 is fixed. The base end of the upper separation unit 603 is attached to the other end of the first arm 602. In the upper separating unit 603, an upper separation plate 603b is attached to a tip end portion of an upper separation support base 603a, and the upper separation mylar 6 is sandwiched by the upper separation plate 603b.
03c and the double feed prevention sheet 603d are attached.

A shaft 604 is rotatably supported by the housing of the paper feeding device 102 at a position where the tip of the shaft 601 partially intersects. A cam 605 is fixed to the shaft 604. An engagement piece 606, one end of which can be engaged with the cam 605, is fixed to the shaft 601. The engaging piece 606 is attached with the other end of a coil spring (not shown) whose one end is fixed to the housing of the sheet feeding device 102. The coil spring applies a biasing force to the cam 605 to push the cam 605 toward the upper separation roller 204B side. At the time of upper separation sheet feeding, the engagement piece 606 is in contact with the short diameter portion of the cam 605.

On the other hand, the shaft 601 has a torsion coil spring 6
07 is attached. This torsion coil spring 60
One upper end of the sheet feeding device 7 is fixed to the housing of the sheet feeding device 102. The other lower end of the torsion coil spring 607 is bent in a direction perpendicular (front side) to the paper surface. The second portion fixed to the shaft 601 in a state in which the bent portion is pushed back in a direction opposite to the biasing direction of the torsion coil spring 607.
It is hooked on the arm 608.

A torsion coil spring 609 is attached to the upper shaft 308. One upper end of the torsion coil spring 609 is fixed to the housing of the sheet feeding device 102.
The other lower end of the torsion coil spring 609 is bent in the direction perpendicular (front side) to the paper surface. The bent portion lightly urges the connecting member 311.

Further, an upper separating sheet 621 is provided between the upper pickup roller 203B and the upper separating roller 204B so that the leading end thereof is located below the original conveying path. The upper separating sheet 621 contacts the document to separate the document and separates the document from the separation rollers 204A, 2A.
It works to lead to 04B.

The shaft 6 is parallel to the lower shaft 309 at a predetermined distance.
10 is rotatably supported by the housing of the paper feeding device 102. A fan-shaped gear 611 is fixed to the shaft 610. Further, one end of the first link 612 is fixed to the shaft 610. The other end of the first link 612 is connected to the second link 61.
3 is connected to one end. The other end of this second link 613 has a rib 614A formed on the lower separation plate 614.
Is connected with. The lower separating plate 614 has a shaft 615.
It is rotatably attached to. At the time of upper separation sheet feeding, the lower separation plate 614 is held in a state of protruding to the lower separation position.

On the other hand, an arcuate double feed prevention pad support 616 is arranged so as to surround the lower pickup roller 203A from the outside. A base end portion of the double feed prevention pad support 616 is rotatably supported by a shaft 617. Axis 6
A protrusion 618 is formed in the vicinity of 17 and on the side of the lower pickup roller 203A. The third link 619 connects the protrusion 618 and the first link 612. At the time of upper separation sheet feeding, the front end portion of the double feed prevention pad support 616 is held in a state of protruding to the upper end surface of the lower pickup roller 203A. A double-feed prevention pad 6 is provided at this tip.
Twenty is attached. The double feed prevention pad 620 is
It is made of a material such as felt having a smaller friction coefficient than the lower pickup roller and a larger friction coefficient than the original paper. The multi-feed preventing pad 620 prevents the layers of a large number of original sheets from entering between the upper separation roller 204B and the lower separation roller 204A when the remaining original sheets are small and only one original is placed on the original placing table 201. Document is prevented from being stopped when it becomes.

FIG. 7 shows a state where the lower separation sheet feeding of the sheet feeding device is performed. As shown in FIG. 7, when the lower separation feeding is performed, the long diameter portion of the cam 605 is in an upright state. The engagement piece 606 is in contact with the long diameter portion of the cam 605. At this time, the upper handling unit 603
7 is guided by a guide (not shown) to move to the state shown in FIG. 7, and the double feed prevention sheet 603d is held in a state of protruding to the upper separation position.

The torsion coil spring 607 is brought into the state shown in FIG. 7 in conjunction with the movement of the second arm 608.
At this time, the bent tip portion of the torsion coil spring 607 abuts on the side wall of the connecting member 311. As a result, the load applied to the upper pickup roller 203B is increased, and the pickup pressure during the lower separating operation is higher than that during the upper separating operation.

On the other hand, the fan-shaped gear 611 rotates clockwise, and the double feed prevention pad support base 616 is separated from the lower pickup roller 203A. At this time, the double feed prevention pad 620 is attached to the lower pickup roller 2
It is in a state of being retracted from the upper end surface of 03A.

Upper sorting unit 603 and lower sorting plate 6
The shafts 604 and 610 which operate 14 are interlocked by a guide interlocking mechanism. FIG. 8 shows the structure of this guide interlocking mechanism.

As shown in FIG. 8, a pulley 803 fixed to the tip of the drive shaft of the motor 801 and one end of the shaft 802 of the registration roller 205 is connected by a belt 804. The first gear 805 is fixed to the other end of the shaft 802. The first gear 805 is a gear 80 to which the shaft 604 is fixed via a plurality of gears including intermediate gears 806 and 807.
8 and a fan-shaped gear 611. As a result, the driving force of the motor 801 is transmitted through the gears to the shaft 604 and the shaft 6.
10 is transmitted.

First gear 805 and intermediate gears 806, 807
A gear 812, whose position is controlled by a mechanical clutch 809, between which the driving force from the motor 801 is turned on and off.
Are arranged. That is, the mechanical clutch 809 is
When transmitting the driving force from the motor 801, the gear 8
12 is moved to the meshing position with the gear 810, and the driving force is transmitted via a plurality of gears such as the gear 813 and the intermediate gears 806 and 807. When cutting the driving force from the motor 801, the gear 812 is moved to a position where it does not mesh with the intermediate gears 806 and 807. The mechanical clutch 809 is electrically controlled by the solenoid 811.

Next, the operation of the sheet feeding device having the above-mentioned configuration will be described separately for the case of performing the upper separation sheet feeding and the case of performing the lower separation sheet feeding. 9 (A) to 9 (C) are diagrams showing the operation of the sheet feeding device when performing the upper separation sheet feeding.
FIG. 10A to FIG. 10C are diagrams showing the operation of the sheet feeding device when the lower separation sheet feeding is performed. The paper feeding device 10
In the description of the switching operation of the state 2 described above, in the operation of switching to the state of performing upper separation sheet feeding (hereinafter, referred to as “upper separation sheet feeding state”), the state of performing lower separation sheet feeding before switching (hereinafter,
It is assumed that it is a “lower separated sheet feeding state”), and the opposite is true in the operation of switching to the lower separated sheet feeding state.

When the upper separation paper feeding is performed, first, the paper feeding device 1
It is necessary to set the No. 02 state from the lower separated sheet feeding state shown in FIG. 10 (A) to the upper separated sheet feeding state shown in FIG. 9 (A). The sheet feeding device 102 is set in the upper separated sheet feeding state as follows.

First, under the control of the solenoid 811, the mechanical clutch 809 moves the position of the gear 812 to move the gear 8
12 is meshed with a plurality of gears such as intermediate gears 806 and 807. As a result, the driving force of the motor 801 is transmitted to the shaft 604 and the shaft 610 via a plurality of gears such as the intermediate gears 806 and 807. That is, the axis 802
Functions only to rotate the registration roller 205 when the gear 812 does not mesh with a plurality of gears such as the intermediate gears 806 and 807.
When it meshes with a plurality of gears such as 06 and 807, it functions as a part of the guide interlocking mechanism. Mechanical clutch 809
The shaft 80 by moving the position of the gear 812.
Switching the function of 2.

Under the control of the solenoid 811, the mechanical clutch 809 moves the gear 812 to a position where it does not mesh with a plurality of gears such as the intermediate gears 806 and 807 after a lapse of a certain time. This is, for example, after switching the state of the sheet feeding device 102 from the upper separation sheet feeding state to the lower separation sheet feeding state,
This is to stop the 02 from continuing to function as a part of the guide interlocking mechanism. Further, the reason why the gear 812 is moved after a lapse of a certain period of time is that a sensor or the like for detecting the state of the sheet feeding device 102 is provided so as not to complicate the internal mechanism of the sheet feeding device 102. Therefore, the present paper feeding device 1
In No. 02, the gear 813 has a built-in torque limiter having a slip torque. The torque limiter absorbs the driving force from the motor 801 until a certain time elapses after the state of the sheet feeding device 102 is switched, and the shaft 60
4 and the shaft 610 are not transmitted.

Next, the motor 801 rotates the shaft 802 in the direction of arrow A in FIG. First in conjunction with the rotation of the shaft 802
When the gear 805 rotates, the gear 808 having the shaft 604 fixed thereto passes through a plurality of gears including the intermediate gears 806 and 807.
The fan-shaped gear 611 rotates in the direction of arrow C in FIG. As a result, the shaft 604 and the shaft 610 rotate in the same direction in conjunction with the rotation of the gear 808 and the fan-shaped gear 611.

When the shaft 604 rotates, the cam 605 fixed to the shaft 604 rotates in the same direction together with the shaft 604 and comes into contact with a stopper (not shown) to be in the state shown in FIG. 9 (A). At this time, the engaging piece 606 rotates clockwise by the force of the coil spring (not shown) fixed to the engaging piece 606 to return. The shaft 601 rotates in the same direction in conjunction with the movement of the engagement piece 606. This allows the shaft 6
The tip portion of the first arm 602 fixed to 01 moves upward. In association with the movement of the first arm 602, the upper separation unit 603 is held in a state of being moved to the position shown in FIG. 9 (A).

The second arm 608 fixed to the shaft 601 moves upward in association with the clockwise rotation of the shaft 601. The lower end of the torsion coil spring 607 is lifted upward in association with the movement of the second arm 608. At this time, the bent tip portion of the torsion coil spring 607 is also lifted, and the tip portion is connected to the connecting member 3.
Leave side wall 11 As a result, the biasing force applied to the connecting member 311 is only the biasing force of the torsion coil spring 609.

On the other hand, when the fan-shaped gear 611 and the shaft 610 rotate, the tip end portion of the lower separation plate 614 connected to the shaft 610 via the first link 612 and the second link 613 pushes upward with the shaft 615 as a fulcrum. As a result, the state of protruding to the lower separation position shown in FIG.
Further, the double feed prevention pad support 616 connected to the first link 612 by the third link 619 is pulled toward the lower pickup roller 203A side with the shaft 617 as a fulcrum. At this time, as shown in FIG.
03A is held in a state of protruding to the upper end surface. At this time, the multi-feed prevention pad 620 attached to the tip of the multi-feed prevention pad support 616 is inserted below the lowest document.

As described above, the state of the sheet feeding device 102 is set from the lower separation sheet feeding state shown in FIG. 10A to the upper separation sheet feeding state shown in FIG. 9A. In this way, after the state of the sheet feeding device 102 is set to the upper separation / feeding state, the upper separation / feeding of the document is started. The upper separation and feeding of the original document is performed as follows.

First, the motor 301 rotates the connecting gear 303 in the direction of arrow C in FIG. The upper shaft 308 and the lower shaft 309 rotate in the direction of arrow B in FIG. 3 in association with the rotation of the connecting gear 303. When the upper shaft 308 rotates, the pulley 312 attached to the upper shaft 308 via the one-way clutch 501 and the upper separation roller 204B attached to the upper shaft 308 rotate in the same direction. On the other hand, when the lower shaft 309 rotates, the pulley 315 attached to the lower shaft 309 and the lower separation roller 204A rotate in the same direction.

Here, the mechanism in which the upper separation roller 204B rotates in the same direction in conjunction with the rotation of the upper shaft 308 will be described with reference to FIG. In FIG. 4, when the upper separation sheet feeding is performed, the upper shaft 308 rotates in the arrow C direction in FIG. When the upper shaft 308 rotates, the limiter boss 403 fixed to the upper shaft 308 by the parallel pin 405 rotates in the same direction. The limiter spring 404 is the limiter boss 403.
Since it is tightened between the fixed boss 402 and the fixed boss 402, the rotation of the limiter boss 403 is transmitted to the fixed boss 402. Since the fixed boss 402 is fixed to the roller base 204B-1, when the fixed boss 402 rotates, the roller base 204B-1 also rotates in the same direction. In this way, the upper separation roller 204B is adapted to rotate in the same direction as the upper shaft 308. The same applies to the case where the lower separation roller 204A rotates in the same direction in conjunction with the rotation of the lower shaft 309.

A one-way clutch 501 is attached to the upper shaft 308.
The pulley 312 and the lower shaft 30 attached via the
When the pulley 315 attached to 9 rotates to the forward rotation side, the belts 314 and 317 cause the respective pulleys 312,
Pulleys 313 and 316 connected to 315 rotate in the same direction. As the pulleys 313 and 316 rotate, the upper pickup roller 203B and the lower pickup roller 203A also rotate in the same direction.

Now, the relationship between the upper pickup roller 203B and the original will be described. If the original is not fed in the upper separation feeding state, the torsion coil spring 609
Indicates that the connecting member 311 is lightly biased.
The vertical mechanism of the pickup roller will be described with reference to FIG. Further, a swinging member 319, a solenoid 320 for electrically controlling the swinging member 319, and a return spring 321 for returning to the original position of the swinging member 319 moved by the solenoid are arranged on the opposite side of the connecting member 311 from the roller. The connecting member 311 holding the upper pickup roller 203B is not fixed to the housing of the sheet feeding device 102 or the like, and is returned by the return spring 321 via the swinging member 319 with the upper shaft 308 as a fulcrum. The uppermost original is lifted to a position where the upper pickup roller 203B does not come into contact with it. When the original is separated and fed, the swinging member 319 is rotated by the solenoid 320 in the direction of arrow A in the figure. Therefore, the upper pickup roller 203B pivotally supported by the connecting member 311 has its own weight and the torsion coil spring 609. The upper shaft 308 is used as a fulcrum to move to the document side, and to the pickup position for picking up the uppermost document. When the document is fed, the swinging member 319 moved by the solenoid 320 moves the return spring 3
By being returned to the original position by 21, the upper pickup roller 203B is lifted to a position where it does not contact the uppermost document.

When the upper pickup roller 203B and the lower pickup roller 203A rotate, the sheet feeding device 10
The state 2 is the state shown in FIG. 9 (B). FIG. 9 (B)
As shown in FIG. 9, as the upper separation roller 204B rotates, the upper pickup roller 203B rotates in the direction of arrow A in FIG. 9B while pressing the uppermost document, and moves the document to the separation rollers 204A and 204B side. Feed the paper. At this time,
Since the upper pickup roller 203B and the lower pickup roller 203A are arranged at positions facing each other with the original interposed, the force of the upper pickup roller 203B pressing against the original can be applied to the original without escaping. In this state, the upper pickup roller 203B rotates to feed the document, so that the document can be efficiently fed.

Generally, the upper pickup roller 203B
If the paper is fed in, a bundle of a plurality of documents will be fed due to a frictional force between the documents. For this reason, as shown in FIG. 9B, the lower separation plate 614 is arranged at a position in contact with the document bundle in order to separate a plurality of fed document bundles in the upper sheet feeding state. As a result,
The highest rank is sent first or separated into a smaller number of sheets than a plurality of fed sheets. The documents separated by the lower separation plate 614 are separated by the separation rollers 204A and 204B.
Is guided to the contact surface of.

FIG. 9C shows the state of the sheet feeding device 102 when the bundle of a plurality of fed sheets is not separated into only the uppermost one sheet by the lower separating plate 614. In FIG. 9C, the two originals are separated by the separation roller 204.
The state of the paper feeding device when paper is fed to the contact surfaces A and 204B is shown. As shown in FIG. 9C, when two originals are fed to the separation rollers 204A and 204B, the upper separation roller 204B rotates in the direction of arrow A in FIG. 9C and the lower separation roller 204A moves. It is rotating in the direction of arrow B in FIG. 9 (C). As a result, of the two fed originals, the original placed below is returned to the pickup rollers 203A and 203B by the rotation of the lower separation roller 204A. As a result, the document passing between the lower separation roller 204A and the upper separation roller 204B is separated into only the uppermost one sheet.

Lower separation roller 204A and upper separation roller 20
When only the uppermost one document passes between 4B and 4B, the lower separation roller 204A rotates in the direction of arrow C in FIG. 9C. That is, the torque limiter built in the lower separation roller 204A is used to lower the lower separation roller 204A.
Are adapted to rotate with the upper separation roller 204B.

Here, the mechanism by which the lower separation roller 204A rotates together will be described. When there are two or more originals between the lower separation roller 204A and the upper separation roller 204B, the friction coefficient between the originals is smaller than the friction coefficient between the lower separation roller 204A and the originals.
Lower separation roller 204 through the document sandwiched from 4B
The torque applied to the lower separation roller 204 A is lower than the lower separation roller 204 A through a torque limiter built in the lower separation roller 204 A.
Since the reverse rotational force applied to A is larger, the lowest original that is in contact with the lower separation roller 204A is returned in order. Lower separation roller 204A and upper separation roller 2
When only the uppermost one document passes between the upper separation roller 204B and the upper separation roller 04B, the rotational force applied to the lower separation roller 204A through the original sandwiched between the upper separation roller 204B and the torque built in the lower separation roller 204A. The reverse rotation force applied to the lower separation roller 204A through the limiter is exceeded. That is, the torque limiter built in the lower separation roller 204A operates, and the limiter spring 404 tightened in the limiter boss 403 slips. As a result,
The lower separation roller 204A idles independently of the rotation of the lower shaft 309 and rotates with the upper separation roller 204B. Accordingly, only the uppermost original can be fed when the upper separation feeding is performed.

In this way, the upper separation sheet feeding is performed. Even when three or more originals are fed when the lower separation plate 614 does not separate the uppermost one, the lower overlapping rollers 204A sequentially stack the originals on the pickup rollers 203A and 203B side. Since it is returned to, it is possible to feed only the top document.

On the other hand, when the lower separation sheet feeding is performed, first, the state of the sheet feeding device 102 is set from the upper separation sheet feeding state shown in FIG. 9A to the lower separation sheet feeding state shown in FIG. 10A. There is a need. The sheet feeding device 102 is set in the lower separated sheet feeding state as follows. The position of the gear 812 moves under the control of the solenoid 811, and after a certain time elapses, the gear 81 moves.
The operation until the position 2 is returned is the same as that in the case of setting the upper separation sheet feeding state, and therefore the description is omitted.

When the lower separation sheet feeding is performed, the motor 801 is used.
Rotates the shaft 802 in the direction of arrow B in FIG. Axis 802
When the first gear 805 rotates in association with the rotation of No. 1, the gear 808 fixed to the shaft 604 and the fan-shaped gear 611 rotate in the direction of arrow D in FIG. 8 via a plurality of gears including the intermediate gears 806 and 807. . As a result, the shaft 604 and the shaft 6 are interlocked with the rotation of the gear 808 and the fan-shaped gear 611.
10 rotates in the same direction.

When the shaft 604 rotates, the cam 605 fixed to the shaft 604 rotates in the same direction as the shaft 604 and comes into contact with a stopper (not shown) to bring the state shown in FIG. At this time, the engagement piece 606 is pushed up by the cam 605 and rotates in the counterclockwise direction. Engagement piece 60
The shaft 601 rotates in the same direction in conjunction with the movement of 6.
As a result, the tip of the first arm 602 fixed to the shaft 601 moves downward. In association with the movement of the first arm 602, the upper separation unit 603 is guided by a guide (not shown) and is held in a state of being moved to the position shown in FIG. 10 (A). At this time, the double feed prevention sheet 603d of the upper separating unit 603 is in a state of being pushed out to the upper separation position shown in FIG.

The second arm 608 fixed to the shaft 601 moves downward in association with the counterclockwise rotation of the shaft 601. The lower end of the torsion coil spring 607 moves downward in response to the movement of the second arm 608 by the force of the torsion coil spring 607 itself to return. At this time, the bent tip portion of the torsion coil spring 607 also moves downward, and the tip portion comes into contact with the side wall of the connecting member 311. As a result, the biasing force applied to the connecting member 311 is the sum of the biasing forces of the torsion coil spring 609 and the torsion coil spring 607.

On the other hand, when the fan-shaped gear 611 and the shaft 610 rotate, the lower separation plate 614 connected to the shaft 610 via the first link 612 and the second link 613 is pulled down with the shaft 615 as a fulcrum. 10
It is held in a state of being moved to the position shown in (A). Also,
The double feed prevention pad support 616 connected by the third link 619 near the circumference of the fan-shaped gear 611 is separated from the lower pickup roller 203A with the shaft 617 as a fulcrum. At this time, the tip of the double feed prevention pad support 616 is held in a state of being retracted from the upper end surface of the lower pickup roller 203A, as shown in FIG. Therefore, the upper end surface of the lower pickup roller 203A comes into direct contact with the document.

As described above, the state of the sheet feeding device 102 is set from the upper separation sheet feeding state shown in FIG. 9A to the lower separation sheet feeding state shown in FIG. 10A. In this way, after the state of the sheet feeding device 102 is set to the lower separation / feeding state, the lower separation / feeding of the document is started. The lower separate feeding of the original document is performed as follows.

First, the motor 301 rotates the connecting gear 303 in the direction of arrow D in FIG. The upper shaft 308 and the lower shaft 309 rotate in the direction of arrow A in FIG. 3 in association with the rotation of the connecting gear 303. When the upper shaft 308 rotates, the one-way clutch 401 acts and the upper separation roller 204
Stop the rotation of B. As a result, the limiter spring 404
The limiter boss 403 slips. Thereby, the upper shaft 30
8 rotates in the direction of arrow A in FIG. 3 independently of the upper separating roller 204B. At this time, the upper pickup roller 203
In B, no pressing force is applied to the original. As a result, it is possible to prevent double feeding which may occur when the pressing force is applied to the original document too much. Also, the pulley 3
Since the one-way clutch 401 is built in 12 and the pulley 313, the pulley 312 and the pulley 313 stop, and the upper pickup roller 203B also stops.

On the other hand, when the lower shaft 309 rotates, the lower separation roller 204A rotates in the same direction as the upper separation roller 204B. When the lower shaft 309 rotates, the pulley 315 with the built-in one-way clutch 401 rotates in the same direction. As a result, the pulley 316 connected by the belt 317 also rotates in the same direction, and the lower pickup roller 203A also rotates in the same direction.

When the lower pickup roller 203A rotates, the state of the sheet feeding device 102 becomes as shown in FIG. 10 (B). As shown in FIG. 10B, the lower separation roller 20
With the rotation of 4A, the lower pickup roller 203A
The original is fed to the separation rollers 204A and 204B by rotating in the direction of arrow D in FIG. 10B while contacting the lowest original.

When the lower pickup roller 203A feeds paper as in the case of the upper separation paper feed, a bundle of a plurality of originals is fed due to a frictional force between the originals. Therefore, as shown in FIG. 10B, in order to separate a plurality of fed document bundles, the multi-feed preventing sheet 603 attached to the upper separating sheet 621 and the upper separating unit 603 is separated.
It is arranged at a position where d contacts the bundle of documents. As a result, the originals are ordered so that the lowest paper is fed first, and separated into one or several layers of the lowest paper.

In FIG. 10C, the double feed prevention sheet 60
3 shows a state of the sheet feeding device 102 when a plurality of document bundles fed by 3d are separated into only the lowest one sheet. Before a document is fed between the upper separation roller 204B and the lower separation roller 204A, the upper separation roller 204B is
It rotates along with the lower separation roller 204A and rotates in the normal direction. In the present paper feeding device 102, the upper separation unit 603 for separating the document is separated by the separation roller 204A when the lower separation paper is fed.
It projects to the vicinity of 204B. Therefore, when the upper separation roller 204B is rotated in the reverse direction, the original is separated by the upper separation unit 6
It may enter the back side of 03 and bend. In order to prevent this, in the present paper feeding device, when a plurality of document bundles enter between the lower separation roller 204A and the upper separation roller 204B, the one-way clutch 4
By the function of 01, the reverse rotation of the upper separation roller 204B is stopped, so that the document is prevented from being bent due to the relationship with the double feed prevention sheet 603d.

On the other hand, in the present paper feeding apparatus 102, the lower separation roller 204A is set to rotate in the reverse direction during the upper separation operation. This is when the upper separation feeding
This is because there is no document separating member that projects to the vicinity of the separation rollers 204A and 204B unlike the upper separating unit 603 during the lower separating operation. Therefore, even during the upper separating operation, as in the lower separating operation, the separation roller 204
When the document separating member is projected to the vicinity of A and 204B, it is necessary to stop the reverse rotation of the lower separation roller 204A by the one-way clutch 401 or the like.

As shown in FIG. 10C, when only the lowest document is fed, the torque limiter built in the upper separation roller 204B is the same as the lower separation roller 204A in the case of upper separation feeding. The upper separation roller 204B is rotated by the lower separation roller 204A. As a result, only the lowest document can be fed when the lower separation feeding is performed.

Further, in general, the lower pickup roller 2
When the paper is fed by 03A, the paper is fed to the lowest original among the originals placed on the original table 201.
A larger pickup pressure is required than in the case of performing upper separation paper feeding. For this reason, in the paper feeding apparatus 102, when the lower separation paper feeding is performed, the biasing force of both the torsion coil spring 609 and the torsion coil spring 607 is applied to the connecting member 311. Therefore, the force of the upper pickup roller 203B pressed against the original document via the connecting member 311 is larger than that in the upper separation sheet feeding state. As a result, the original is strongly pressed downward as compared with the case of performing the upper separation feeding, so that the lower pickup roller 203A
Can apply a large pickup pressure to the document.

As described above, according to the sheet feeding device of the present embodiment, the separation rollers 204A and 204B and the pickup rollers 203A and 203B are connected to each other, and the separation roller 204
Pick-up roller 2 linked to the rotation of A and 204B
By rotating 03A and 203B, the pickup rollers 203A and 203B feed the originals, and when a plurality of original bundles are fed, the separation roller 2
Since 04A and 204B separate the bundle of originals, both upper and lower separate feeding of the originals can be performed by a simple mechanism and control.

Further, according to the paper feeding device of the present embodiment,
Since the pickup rollers 203A and 203B are arranged at positions facing each other with the original sandwiched therebetween, the force of the upper pickup roller 203B pressing against the original can be applied to the original without escaping, so that the original can be efficiently fed. It can be performed. Further, the upper pickup roller 20
Since 3B is provided so as to be able to move up and down, it is not necessary to add documents even when feeding a large number of documents, so that workability in the paper feeding device can be improved.

Further, according to the sheet feeding device of the present embodiment,
A torque limiter is built in the upper and lower separation rollers 204A and 204B so that the original is placed between the separation rollers 204A and 204B.
Since it is set so as to be rotated in the paper feed direction when only one sheet is fed, only the uppermost or lowermost original can be fed.

Further, according to the paper feeding device of the present embodiment,
When performing lower separation feeding, the upper separation roller 204B is prevented from rotating in the reverse direction due to the action of the one-way clutch 401. Therefore, the upper separation roller 204B rotates in reverse to return the original to the pickup rollers 203A and 203B side. It is possible to prevent the original from being bent.

Further, according to the sheet feeding device of the present embodiment,
Since the upper and lower separation rollers 204A and 204B rotate in association with the rotation of the single coupling gear 303 and the switching between the upper separation paper feed and the lower separation paper feed is performed by the same drive source, The internal structure of the device can be simplified.

Further, according to the paper feeding device of the present embodiment,
When performing lower separation paper feeding, two torsion coil springs 607,
By urging the connecting member 311 with 609, the force of the upper pickup roller 203B pressed against the original is increased, so that the pickup pressure of the original when the lower separate feeding is performed is higher than when the upper separate feeding is performed. Can be increased. As a result, it becomes easy to feed the lowest document that is difficult to feed due to differences in the basis weight and smoothness of the document.

Further, as shown in FIG. 12, the surface of the lower pickup roller 203A may be changed to an uneven shape when the lower separation sheet feeding is performed. With such a change, the pick-up force can be further increased as compared with the present embodiment, so that the lowest original that is difficult to be fed due to the difference in the basis weight and smoothness of the original is further fed. It will be easier.

[0101]

As described above, according to the present invention,
By connecting the separation roller and the pickup roller and rotating the pickup roller in conjunction with the rotation of the separation roller, the pickup roller feeds the originals and when a bundle of a plurality of originals is fed, Since the separating roller separates the original bundle, it is possible to perform both upper and lower separate feeding of originals with a simple mechanism and control, and to provide a paper feeding apparatus excellent in workability. You can

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a multifunction machine equipped with a sheet feeding device according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of the sheet feeding device according to the above embodiment.

FIG. 3 is a perspective view of a drive system from a motor to a separation roller and a pickup roller in the paper feeding device according to the above embodiment.

FIG. 4 is a perspective view showing the inside of an upper separation roller and an upper pickup roller in the paper feeding device according to the embodiment.

FIG. 5 is a cross-sectional view of an upper separation roller and an upper pickup roller in the paper feeding device according to the above embodiment.

FIG. 6 is a diagram showing an upper separation sheet feeding state in the sheet feeding device according to the embodiment.

FIG. 7 is a diagram showing a lower separation sheet feeding state in the sheet feeding device according to the embodiment.

FIG. 8 is a schematic configuration diagram of a guide interlocking mechanism in the sheet feeding device according to the above embodiment.

FIG. 9 is a schematic configuration diagram for explaining an operation of the sheet feeding device when performing upper separation sheet feeding in the sheet feeding device according to the above-described embodiment.

FIG. 10 is a schematic configuration diagram for explaining the operation of the sheet feeding device when performing lower separation sheet feeding in the sheet feeding device according to the above embodiment.

FIG. 11 is a perspective view of an up / down mechanism of a pickup roller in the paper feeding device according to the embodiment.

FIG. 12 is a schematic configuration diagram showing a modified example of the sheet feeding device according to the above embodiment.

[Explanation of symbols]

100 MFP 101 Device body 102 paper feeder 201 Document Plate 202 paper ejection tray 203 Pickup roller 204 separation roller 205 Registration roller 206 Conveyor roller 207 Paper ejection roller 208 roller bracket 306 Upper gear 307 Lower gear 308 Upper shaft 309 Lower shaft 311 Connecting member 319 Swing member 320 solenoid 321 Return spring 401 one-way clutch 402 Fixed boss 403 Limiter Boss 404 Limiter spring 405 parallel pin 501 one-way clutch 601 axis 602 1st arm 603 Upper handling unit 604 axis 605 cam 606 engagement piece 607 torsion coil spring 608 Second arm 609 torsion coil spring 610 axis 611 fan-shaped gear 612 First Link 613 second link 614 Lower handling plate 616 Double feed prevention pad support 619 Third Link 620 Double feed prevention pad 621 Upper handling sheet 806 Intermediate gear 807 Intermediate gear 809 Mechanical clutch 811 solenoid

Front page continuation (72) Inventor Koji Endo 2-3-8 Shimomeguro, Meguro-ku, Tokyo Matsushita Transmission System Co., Ltd. (72) Inventor Takahisa Araki 2-3-8 Shimomeguro, Meguro-ku, Tokyo Matsu Shimo Electric Transmission Co., Ltd. (72) Inventor Kazuo Watanabe 2-3-8 Shimomeguro, Meguro-ku, Tokyo Matsushita Electric Transmission Co., Ltd. (56) Reference JP-A-60-67333 (JP, A) Flat 8-202088 (JP, A) JP 10-279095 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B65H 3/52 310 B65H 3/52 330 G03G 15/00 107

Claims (6)

(57) [Claims] 1. A pair of separating rollers for separating the original bundle one by one , a pair of pickup rollers for feeding the original bundle from the original placing table to the pair of separating rollers, the pair of separating rollers and the pair of pickup rollers. Between the upper side and the separating means for advancing onto the conveying path to contact the original and separating the original, and the contact portion between the original stack and the separating means for moving from the lower side to the conveying path on the upstream side of the original conveying direction. Lowering means for preventing the lower part of the original stack of documents from being conveyed,
On the downstream side of the original conveying direction of the contact portion, a double feed preventing unit that moves from above to above the conveying path to prevent the upper portion of the original bundle from being conveyed, and the lower document when separating the uppermost original from the original bundle The separating means is moved to prevent the lower part of the original stack from being conveyed.On the other hand, when separating the lowermost original from the original stack, the double feed prevention means is moved so that the separating means first comes into contact with the originals. And a separation unit that separates the originals and then prevents the upper portion of the original bundle from being conveyed by the double feed prevention unit. 2. A second pair of pickup rollers is moved to a position covering the surface of the lower pickup roller so that the lowermost surface of the document stack is not in contact with the surface of the lower pickup roller.
2. The sheet feeding device according to claim 1, wherein the double feed preventing unit is provided, and the second double feed preventing unit moves to the position when separating the lowest document from the document stack. 3. The sheet feeding device according to claim 2, wherein the second double feed preventing means is formed of a material having a friction coefficient smaller than that of the surface of the lower pickup roller and a friction coefficient larger than that of the original. . 4. The pickup pressure for the original stack placed on the original table is greater when separating the lowermost original from the original stack than when separating the uppermost original from the original stack. The sheet feeding device according to claim 1, wherein the sheet feeding device is a sheet feeding device. 5. on the separation roller of the pair of separation rollers, when separating the original top-level from the document bundle, is rotated in the direction of conveying the document, in the case of separating the lowermost original from the original stack, When multiple originals are fed, rotation stops and
When only the lowermost original is fed, the lower separating rollers of the pair of separating rollers rotate together, while the lower separating roller separates the uppermost original from the original bundle .
When multiple originals are fed When the originals are rotated in the opposite direction to the original feed direction and only the topmost original is fed
2. The sheet feeding device according to claim 1, wherein the sheet feeding device rotates in accordance with the rotation of the upper separation roller, and rotates in a direction in which the document is conveyed when the lowest document is separated from the document stack. 6. An image recording apparatus using the sheet feeding device according to claim 1.