JP3349909B2 - Paper feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeder used for a paper feed unit such as a stack bypass of an image forming apparatus such as a copying machine or a facsimile machine, and for supplying transfer paper.

[0002]

2. Description of the Related Art Conventionally, this type of paper feeder has been used, for example, in a stack bypass of a manual paper feeder in an image forming apparatus such as an analog copier, and has an upper paper feed roller and a lower paper feeder. The transfer paper is sandwiched by a pair of rollers composed of rollers and taken in. An example of this conventional paper feeder will be described below with reference to FIG.

FIG. 4 is a perspective view of a main part showing a schematic configuration of a sheet feeding device in a conventional image forming apparatus.

In FIG. 4, rotating shafts 82 and 83 are rotatably extended vertically parallel between both side walls (the other side wall is not shown) 81 of the stack bypass of the manual sheet feeding unit via a bearing (not shown). Have been. A feed roller 84 is provided at an appropriate position of the one rotating shaft 82 by a one-way gear (not shown).
The separation roller 85 is disposed on the other rotating shaft 83 so as to face the paper feed roller 84 via a torque limiter 86. A roller pair 8 composed of the paper feed roller 84 and the separating roller 85
7, the transfer sheets 88 are sandwiched between them, and they are rotated in predetermined directions (rotational directions of arrows A and B) so that the transfer sheets 88 are transported one by one in the direction of arrow C inside the apparatus. Has become.

A gear 89 is fixedly provided at one end of the rotating shaft 82, and a gear 90 is also fixedly provided at one end of the rotating shaft 83. An idle gear 91 is arranged between these gears 89, 90 so as to be able to transmit a rotational force. The idle gear 91 has a built-in one-way gear (not shown). The idle gear 91 is connected to a rotating shaft 92 having one end connected to the side wall 81 and fixed via a one-way gear (not shown). It is arranged to be rotatable only in a predetermined direction.

Here, this one-way gear (not shown)
Is a gear that can transmit a rotational force only in one predetermined rotation direction and that idles in a free state in another rotation direction. When the one-way gear (not shown) is locked only in a predetermined direction from the gear to the rotation shaft and can transmit a rotational force, for example, the rotation direction is the same as the rotation direction of the gear at that time. However, when the driving force transmission direction of the gear from the rotation shaft is the reverse direction, the rotation force is not transmitted and the gear idles in a free state.

In this case, the one-way gear (not shown) is incorporated in the idle gear 91 because two or more sheets of transfer paper 88 bite between the paper feed roller 84 and the separation roller 85 and are separated by a slight torque. In order to prevent a so-called double feed in which the roller 85 turns to the take-in side (rotation direction opposite to the rotation direction B) together with the rotation shaft 83 and two or more transfer papers 88 are taken into the apparatus in the direction of arrow C. It is. In other words, when the separating roller 85 tries to rotate in the sheet take-in direction opposite to the rotation direction B during the double feeding, the idle gear 91 is rotated in the reverse rotation direction via the rotation shaft 83 and the gear 90. The idle gear 91 tries to transmit the rotational force in this direction,
One end of the rotating shaft 92 is fixed to the side wall 81, and the idle gear 91 is locked and does not rotate.
Since the rotational force is also transmitted from the gear 89 in the reverse free direction to the idle gear 91 so as to prevent the reverse rotation of the idle gear 91, the separating roller 85 does not rotate in the paper taking-in direction and double feeding is prevented. Is done.

When the torque of the torque limiter 86 exceeds a predetermined torque, the rotation between the rotating shaft 83 and the separating roller 85 is slid so that no torque is transmitted. In other words, when the transfer paper 88 bites between the paper feed roller 84 and the separation roller 85 and a large rotation torque is applied, the rotation force of the separation roller 85 for returning the lower transfer paper 88 to the original position is slid to rotate. By preventing the force from being transmitted, the paper feed roller 84
This is for feeding the upper transfer paper 88 with priority given to the rotation of the side.

With the above configuration, when a copy switch (not shown) is pressed, a motor (not shown) is driven to rotate the gear 89 of the rotating shaft 82. This rotational force is applied to the gear 89
The upper sheet feeding roller 84 acts to rotate in the rotation direction A via the rotation shaft 82 from. Further, the lower separating roller 85 is connected to the idle gear 91, the gear 9 from the gear 89.
Further, while rotating in the rotation direction B via the rotation shaft 83 and returning the lower transfer paper 88 to the original state by the separating roller 85, only the upper transfer paper 88 is moved by the paper feed roller 84 in the arrow direction C inside the apparatus. Feed paper. At this time, the paper feed roller 84 acts to transmit the rotational force by a one-way gear (not shown), and the idle gear 91 transmits the rotational force from the gear 89 to the gear 90 in the free rotation state. .

[0010]

In the above-mentioned conventional configuration,
At the time of the JAM processing for restoring a state in which the transfer paper 88 is jammed between the paper feed roller 84 and the separation roller 85 and the jammed state is restored, the transfer paper 88 is moved in the front direction D opposite to the transport direction of the transfer paper 88 into the apparatus. When the pulling roller 8 is pulled by hand, the pulling roller 8 rotates in a free rotation direction opposite to the direction in which the one-way geared feeding roller 84 transmits the rotating force.
5, the rotation force in the rotation direction B is
To the idle gear 91, and further rotates the paper feed roller 84 from the idle gear 91 via the gear 89 and the rotating shaft 82 in the transport direction of the transfer paper 88 (a rotation direction opposite to the near side direction D). Therefore, the paper feed roller 84 and the idle gear 91 are locked together, the paper feed roller 84 and the separation roller 85 do not rotate, and the clogged transfer paper 88 is removed from the paper supply roller 84 and the separation roller 85. It will take a very large force to pull out from between. In this case, there has been a problem that the transfer paper 88 is torn or torn in the middle.

In order to solve this problem, a configuration is adopted in which the upper and lower rollers are opened and released in conjunction with the operation of pulling the cassette out of the apparatus, for example, in the transfer paper loading section of the cassette. However, when a sheet feeding device including the sheet feeding roller 84 and the separating roller 85 is used for the stack bypass of the manual sheet feeding unit, there is no operation comparable to the above-described cassette drawing operation. In addition to this, there is a need for a separate structure for opening and releasing between the sheet feeding roller 84 and the separation roller 85 in conjunction with the release operation, and the configuration becomes complicated. I was

The present invention solves the above-mentioned conventional problem, and does not require a new release operation or a complicated release mechanism interlocked with the release operation at the time of JAM processing, and can easily and lightly pull out the transfer paper. The purpose is to provide.

[0013]

According to the present invention, there is provided a paper feeder comprising: a paper feed roller for feeding paper; and a separating roller provided opposite to the paper feed roller and rotated in a direction opposite to the rotation direction of the paper feed roller. In the sheet feeding device that supplies one sheet with the sheet feeding roller and the separating roller, a driving force is transmitted in the driving force transmitting direction and the rotating direction in the driving force transmitting path of the sheet feeding roller and the separating roller. A driving force transmitting member that is capable of transmitting and idles in the other driving force transmitting direction and the other rotating direction is provided. Via this driving force transmitting member, the sheet feeding roller and the separating roller can be rotationally driven in respective predetermined rotation directions. And a drive mechanism for rotating the paper feed roller in a direction opposite to the predetermined rotation direction and allowing the loosening roller to idle in the predetermined rotation direction. In this paper feeding device, when the paper feeding roller and the separating roller are separately driven by different driving sources, preferably, the driving mechanism includes a driving force transmitting member built in the bearing portion of the rotating shaft of the separating roller and the paper feeding roller. When the feeding roller and the separating roller are driven by the same drive source, the driving mechanism preferably includes a bearing for the rotating shaft of the separating roller and a driving force transmitting direction of the bearing. The driving force transmitting member may be built in the upstream gear portion.

With this configuration, when the driving source is driven separately and the driving force transmitting member is built in the bearing of the rotating shaft of the loosening roller and the paper feed roller, the paper jammed during the JAM process is pulled from between the rollers. The driving force transmitting member built into the bearing of the rotating shaft of the separating roller has the same rotating direction of the rotating shaft of the separating roller, but the driving force transmitting direction is in the opposite direction. When the jammed paper is pulled from between the rollers, the driving force transmission member built in the paper feed roller rotates in the opposite direction, so that the paper feed roller can rotate easily. Become.

Further, when the driving force transmitting member is built in the bearing of the rotating shaft of the separating roller and the gear portion on the upstream side in the driving force transmitting direction of the bearing by driving by the same driving source, the JAM processing is performed. When the jammed paper is pulled from between the rollers, the driving force transmitting member built into the bearing of the rotating shaft of the separating roller has the same rotating direction of the rotating shaft of the separating roller, but the driving force transmitting direction is opposite. Because there is a roller, the separation roller can easily rotate, and when the jammed paper is pulled from between the rollers, the paper supply roller tries to rotate in the direction opposite to the paper supply rotation direction, and the reverse rotation driving force is The driving force is transmitted to the driving force transmitting member in the driving force transmitting path, and since the driving force transmitting member rotates in the reverse rotation direction, the driving force transmitting member idles and the paper feed roller can easily rotate.

As described above, the driving force transmitting member is provided in at least one of the driving force transmitting paths of the sheet feeding roller and the separating roller, and the driving force transmitting member drives the driving force in one of the driving force transmitting direction and the rotation direction. Since the force can be transmitted and the idle rotation occurs in the other driving force transmission direction and the rotation direction, when the jammed paper is pulled from between the rollers during the JAM processing, the paper feeding roller and the separating roller can easily rotate, and the JAM processing can be performed. Occasionally, a new release operation and a complicated release mechanism linked to the release operation are not required, and the transfer paper can be easily and lightly pulled out.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the embodiments described below.

(Embodiment 1) FIG. 1 is a sectional view showing Embodiment 1 of the internal configuration of an image forming apparatus to which the present invention is applied.

In FIG. 1, an apparatus main body 1 of the image forming apparatus includes a sheet feeding section 2 provided at a lower portion thereof, a sheet conveying section 25 provided above the sheet feeding section 2, and a sheet An image forming unit 30 disposed above the conveying unit 25, a fixing unit 40 disposed on the discharge side of the image forming unit 30, and an upper part of the image forming unit 30 and the fixing unit 40; And a contact glass 60 disposed at the center of the upper surface, and a document holder 70 for pressing a document on the contact glass 60.

The paper feed section 2 is composed of a paper feed cassette 3 and a paper feed roller 4, etc., and is a cassette paper feed section for feeding the transfer paper 5 in the paper feed cassette 3 sequentially from the top by the paper feed roller 4. , A paper feed roller 7, a separation roller 8, and the like. The transfer paper 5 on a mounting table 9, which is arranged on the right side of the apparatus main body 1 so as to be freely housed, is sequentially fed from above as a paper feed roller. The paper feeding unit 10 of the present invention, which will be described later in detail, feeds the paper to the stack bypass by a roller 7 and a separating roller 8 serving as a separating roller.

The paper feed cassette 3 of the cassette paper feed section 6
Is provided with a paper loading plate 12 urged upward by a spring 11, and the uppermost transfer paper 5 stacked and loaded on the paper loading plate 12 is moved in the paper feeding direction of the paper feeding cassette 3. It is locked by a separating claw 13 provided at the upper front part. The outer peripheral portion of the paper feed roller 4 is driven by a drive motor 14 indicated by a dotted line in FIG. It is disposed so as to be rotatable with a rotating shaft that is driven to rotate. The axis direction of the rotating shaft is a direction perpendicular to the sheet feeding direction. Further, the shape of the paper feed roller 4 has a half-moon-shaped portion 4a having a substantially half-moon-shaped cross section, and the outer peripheral portion of the half-moon-shaped portion 4a is formed in an uneven shape to increase friction with the paper surface. ing.

Further, the paper transport section 25 transports the transfer paper 5 from the paper feed cassette 3 by the paper feed roller 4 to a reversing guide 26.
Paper feed unit 6 and a mounting table 9 supplied through the
A pair of transport rollers 27 that transports the transfer paper 5 from any one of the manual paper feed units 10 to the image forming unit 30 through the stack bypass by the paper feed roller 7 and the separating roller 8 A registration roller pair 28 driven in synchronization with the scanning timing of the optical unit 50, and a discharge roller pair 29 for discharging the transfer paper 5 to the outside of the apparatus are provided in the paper transport direction. This registration roller pair 28
Is configured to synchronize the transport timing of the leading end of the transfer sheet 5 with respect to the image transfer unit of the image forming unit 30 with the scanning timing of the optical unit 50.

Further, the image forming section 30 has a photosensitive drum 31 rotatably supported on a shaft, and has a main charging section 32, a developing section 33, a transfer section around the photosensitive drum 31 from the upstream side in the rotation direction. And a separating unit 34, a charge removing unit and a cleaning unit 35.

The main charging section 32 uniformly charges the surface of the photosensitive drum 31 to a predetermined potential. Immediately downstream of the main charging section 32, there is provided an area for exposing the optical image of the original from the optical section 50. An electrostatic latent image is formed on the surface of the photosensitive drum 31 by the image. The developing unit 33 performs development by attaching toner according to the electrostatic latent image. Further, the transfer section and the separation section 34 transfer the toner image on the surface of the photosensitive drum 31 to the transfer paper 5 and separate the transfer paper 5 after the transfer from the photosensitive drum 31. Further, the static elimination unit and the cleaning unit 35 erase residual charges on the surface of the photoconductor drum 31 and clean toner remaining on the surface of the photoconductor drum 31 after transfer.

Further, the fixing section 40 comprises a heating roller 41 and a pressure roller 42 and the like.
This is to fix the transfer toner image on the transfer paper 5 separated from the transfer paper 1. The heating roller 41 has a heater disposed inside the roller, and the pressing roller 42 is formed of a material whose surface is slightly softer than the surface of the heating roller 41, and has a required urging force against the heating roller 41. I'm pushing.

Further, the optical section 50 includes an exposure lamp 51,
A reflector 52 for reflecting the light from the exposure lamp 51 toward the original; and reflecting mirrors 53a, 53b, 53c, 53d, 53e, 53f for guiding the light reflected from the original to a predetermined position.
And an exposure lamp 51, a reflection plate 52, a reflection mirror 53a, and reflection mirrors 53b and 53c.
Is to reciprocate in the left-right direction in FIG. 1 at a predetermined speed, and scans a document image during the forward movement to generate a light image of the document. Also,
These reflecting mirrors 53d and 53e can be moved together with the lens unit 54 to obtain a desired image magnification.

FIG. 2 is a perspective view of a main part showing a schematic configuration of the manual paper feed unit 10 in the image forming apparatus of FIG.

In FIG. 2, the manual paper feed unit 10 has a rotating shaft 16 rotatably wrapped between bearings 17 between both side walls (the other side wall is not shown) 15 of the stack bypass. At the same time, a rotating shaft 18 is rotatably suspended directly below the rotating shaft 16 via a bearing 19. The feed roller 7 is provided at an appropriate position on the one rotary shaft 16.
The separating roller 8 is disposed on the other rotating shaft 18 so as to face the sheet feeding roller 7 with a torque limiter 20 interposed therebetween. In addition, these paper feed rollers 7
Transfer paper 5 between a roller pair comprising
The paper feed roller 7 is rotated in the direction of arrow A to feed the upper transfer sheet 5 in the apparatus internal direction C, and the separating roller 8 is returned to return the lower transfer sheet 5 in the apparatus external direction D. Is rotated in the direction of arrow B so that only the uppermost transfer sheet 5 is taken into the apparatus one by one.

At one end of the rotating shaft 16 projecting from the side wall 15 via the bearing 17, a gear 21 is provided with a rotating shaft 16.
It is arranged so as to be rotatable integrally with the camera. A gear 22 is also fixed to one end of the rotating shaft 18 protruding outward from the side wall 15 via the bearing 19 so as to be rotatable integrally with the rotating shaft 18.
An idle gear 23 is interposed between these gears 21 and 22 so as to be able to transmit a rotational force. This idle gear 2
Reference numeral 3 denotes an end which is rotatable in both directions with respect to a rotation shaft 23 a fixed to the side wall 15. The idle gear 23 does not include a one-way gear (not shown) as in the related art, and in the first embodiment, the one-way gear (not shown) includes the sheet feed roller 7 and the bearing 19.
The gear 22 is a one-way gear, and the one-way gear as the driving force transmitting member can transmit the rotational force only in a predetermined one rotation direction,
In the other rotation direction, the motor runs idle in a free state. Further, the one-way gear (not shown) as the driving force transmitting member can transmit the rotational force only in one predetermined rotational force transmitting direction, but even if the one-way gear tries to rotate in the same direction as the gear rotational direction, The rotational force is not transmitted in the direction opposite to the one rotational force transmitting direction, and the motor rotates in a free state.

Further, a motor 24A is provided so as to be able to drive the gear 21 in a predetermined rotation direction by a drive gear 24a provided on a rotating shaft thereof.

With the above configuration, when the copying operation is started, first, when the manual paper feed unit 10 is used, the mounting table 9 on which the transfer paper 5 is mounted is rotated in a horizontal state and taken out. 5 is placed. In this manner, by setting the mounting table 9 by rotating the mounting table 9 in the horizontal state, it is switched to the paper feed drive side by the manual paper feed unit 10 and the cassette paper feed unit 2
Is not performed. Next, when a copy switch (not shown) is pressed, the motor 24A is driven to rotate,
The drive gear 24a is rotated in a predetermined rotation direction. The rotational driving force of the driving gear 24 a is transmitted from the gear 21 to the rotating shaft 1.
6, the sheet feed roller 7 rotates in the direction of arrow A to act to feed the sheet. In addition, the separating roller 8 includes the gear 2.
Rotational driving force is transmitted from 1 through the idle gear 23, the gear 22, and the rotating shaft 18, so that the gear 1 rotates in the direction of arrow B. As described above, while the lower transfer sheet 5 is returned to the original mounting table 9 by the rotation of the separating roller 8, only the upper transfer sheet 5 is fed into the inside of the apparatus by the feed roller 7 in the arrow direction C. . That is, the transfer paper 5 at the uppermost stage is sent out, and the transfer paper 5 is separated by the separation roller 8 and taken out one by one. At this time, the bearing 19 and the gear 22 act so that the rotational force is transmitted by the one-way gear. Further, the transfer paper 5 is supplied to the transport roller pair 27 via the stack bypass.

When the cassette paper feed unit 2 is used, it is only necessary to press a copy switch (not shown) at the start of the copying operation. While pressing the upper surface of the transfer paper 5 stored on the cassette plate 12 with the uneven outer peripheral portion of the roller 4, the uppermost transfer paper 5 is sent out by the frictional force in the paper feeding direction, and the transfer paper 5 is transferred. 5 is separated by the claws 13 and 1
It is taken out one by one. Further, the transfer paper 5 is reversed by the reversing guide 26 and supplied to the transport roller pair 27.

As described above, the transfer paper 5 is transported by the manual paper feed unit 10 or the cassette paper feed unit 2 to the transfer roller pair 2.
7 and further conveyed to a registration roller pair 28. At this time, the registration roller pair 28 conveys the transfer paper 5 to the transfer unit in synchronization with the conveyance timing of the leading end of the transfer paper 5 and the scanning timing of the optical unit 50.

In the transfer section and the separation section 34, the transfer paper 5 is transferred with a toner image based on the original light image on the surface of the photosensitive drum 31, and the transferred transfer paper 5 is separated from the photosensitive drum 31. You. After that, the separated transfer paper 5 is fixed on the transfer toner image on the transfer paper 5 by the heating roller 41 and the pressure roller 42 of the fixing unit 40, and is discharged onto the discharge tray 71 via the discharge roller pair 29. Will be.

Here, the paper feed roller 7 and the separation roller 8
A description will be given of a JAM process for restoring the transfer paper 5 when the transfer paper 5 is jammed and jammed.

In this case, the transfer sheet 5 is pulled by hand in a direction D which is opposite to the direction in which the transfer sheet 5 is fed into the apparatus (the direction of arrow C). The paper feed roller 7 attempts to rotate in the direction E opposite to the direction in which the transfer paper 5 is fed, and the rotational force is transmitted from the paper feed roller 7 to the rotating shaft 16 and the gear 2 via the bearing 17.
1, the rotational force of the gear 21 is to rotate the one-way gear 22 through the idle gear 23 in the rotational direction F in the free rotation direction (idling direction) in the direction G opposite to the normal drive transmission direction. I do. Therefore, the front direction D
When the transfer paper 5 is pulled by hand, the paper feed roller 7 easily rotates in the pulling direction.

At this time, the roller rotating direction of the separating roller 8 due to the pulling force tends to rotate in the same direction (the direction of arrow B) as the direction in which the transfer paper 5 is returned, and the rotating force is rotated by the separating roller 8. The power is transmitted to the shaft 18 and further to a bearing 19 with a one-way gear. However,
When transmitting the rotational force from the rotating shaft 18 side to the rotating shaft side of the gear 22 via the one-way geared bearing portion 19, the one-way geared bearing portion 19 runs idle in the free rotation state and does not transmit the driving force. Will be. Therefore, when the transfer paper 5 is pulled by hand in the front side direction D, the separating roller 8 also easily rotates with the rotation shaft 18 in the pulling direction, and both the sheet feeding roller 7 and the separating roller 8 are rotated. Therefore, the transfer paper 5 is easily rotated in the pulling-out direction. For this reason, a new release operation and a complicated release mechanism interlocked with the release operation are not required during the JAM processing, and the transfer sheet 5 is not torn or torn in the middle as in the conventional case, and it is easy and light. The transfer paper can be pulled out.

Next, two or more transfer papers 5 are engaged between the feed roller 7 and the separating roller 8, and the separating roller 8 is moved in a sheet feeding direction (a rotation direction opposite to the rotation direction B) with a slight torque.
A so-called double feed prevention mechanism in which two or more transfer sheets 5 are taken in the direction of arrow C inside the apparatus will be described.

When the separating roller 8 tries to rotate in the sheet taking-in direction opposite to the rotating direction B during the double feeding, the rotational force is transmitted to the rotating shaft 18 and the bearing 19 with a one-way gear. The one-way gear (not shown) of the bearing 19 can transmit a rotational force from the rotating shaft 18 to the rotating shaft of the one-way gear 22. Further, as described above, the rotational force is reverse to the normal drive rotational direction, so that the drive force is transmitted from the one-way gear 22 to the idle gear 23 even when the drive force transmission direction is reversed. Although the rotation can be transmitted, the rotational driving force of the motor 24A in the reverse rotation direction is transmitted to the one-way gear 22 via the idle gear 23, and the one-way gear 22 is locked and stops rotating. Will be. Therefore, two or more sheets of transfer paper 5 bite between the paper feed roller 7 and the separating roller 8 and rotate to the side where the separating roller 8 takes in with a slight torque (the rotation direction opposite to the rotation direction B). The so-called double feeding problem in which two or more transfer sheets 5 are taken in the direction of arrow C inside the apparatus is prevented.

Further, even in the case where the transfer sheet 5 is bitten between the paper feed roller 7 and the separation roller 8 and a large rotational torque is applied, the separation roller 8 for returning the lower transfer sheet 5 to the original state is used. The transfer paper 5 can be fed by giving priority to the rotation force of the paper feed roller 7 by making the rotation force slip by the torque limiter 20 so that the rotation force is not transmitted to the separation roller 8.

(Embodiment 2) In the reverse rotation torque limiter system, in Embodiment 1 described above, the feed roller 7 and the separating roller 8 are driven by one motor 24A via the idle gear 23, and the bearing 19 and the gear 22 is provided with a one-way gear. In the second embodiment, the driving of the paper feed roller and the separating roller is separately performed by two motors, and the paper feeding roller and the bearing of the separating roller are provided with a one-way gear. Is the case.

FIG. 3 is a perspective view of a main part showing a schematic configuration of a manual paper feed unit in the image forming apparatus according to the second embodiment of the present invention. The members having the same functions and effects as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

In FIG. 3, a paper feed roller 7 is disposed at an appropriate position on the rotating shaft 16 with a one-way gear (not shown) incorporated therein.
Is disposed facing the paper feed roller 7 with the torque limiter 20 interposed therebetween. Further, the idle gear 23 as in the first embodiment is not provided between the gears 21 and 22a, and the motor 24A drives the gear 21 by the drive gear 24a provided on the rotation shaft thereof in a predetermined rotation direction. The motor 24B is mounted so as to be able to drive the gear 22a in a predetermined rotation direction by a drive gear 24b provided on the rotation shaft. Further, the gear 22a of the second embodiment is not a one-way gear like the gear 22 of the first embodiment. The manual sheet feeding unit 10a is configured as described above.

With the above configuration, at the start of the copying operation, first, when the manual paper feed unit 10a is used, the mounting table 9 on which the transfer paper 5 is mounted is rotated in a horizontal state, and the transfer paper 5 is mounted thereon. I do. In this manner, by rotating the mounting table 9 in the horizontal state, it is switched to the paper feed drive side by the manual paper feed unit 10a, and the paper feed drive by the cassette paper feed unit 2 is not performed. Next, when a copy switch (not shown) is pressed, the motors 24A and 24B rotate in predetermined rotational directions, respectively, and drive the drive gears 24a and 24b, respectively. The rotational driving force of the driving gear 24 a is transmitted from the gear 21 via the rotating shaft 16 to the sheet feeding roller 7.
a rotates in the direction of arrow A and acts to feed paper.
The rotational driving force of the driving gear 24a is the gear 2
Rotational driving force is transmitted from 2a to the separating roller 8 via the rotating shaft 19, and acts in the direction of arrow B to prevent double feeding. In this manner, while the lower transfer sheet 5 is returned to the original mounting table 9 by the rotation of the separating roller 8, only the upper transfer sheet 5 is fed into the inside of the apparatus by the feed roller 7a in the arrow direction C. . That is, the lower transfer paper 5 is separated by the separation roller 8 and the uppermost transfer paper 5 is taken out one by one. At this time, the paper feed roller 7a and the bearing 19 act so that the rotational force is transmitted by a one-way gear (not shown).

Here, a description will be given of a JAM process for restoring the transfer paper 5 when it is jammed between the paper feed roller 7a and the separating roller 8 and jammed.

In this case, the transfer sheet 5 is manually pulled in a direction D, which is opposite to the direction in which the transfer sheet 5 is transported into the apparatus (the direction of arrow C). The direction of rotation of the roller due to the pulling force is as follows. Since the paper feed roller 7a tries to rotate in the direction opposite to the direction in which the transfer paper 5 is fed, and the rotation direction is the reverse direction, the paper feed roller 7a with the one-way gear can easily rotate in the free rotation state. become. At this time,
The direction of rotation of the separating roller 8 by the pulling force is the same as the direction in which the transfer paper 5 is returned (the direction of arrow B).
The rotational force is transmitted from the separating roller 8 to the rotating shaft 18 and further to the bearing 19 with a one-way gear. However, when transmitting the rotational force from the rotating shaft 18 side to the rotating shaft side of the gear 22 via the one-way geared bearing portion 19, the one-way geared bearing portion 19 idles in a free rotation state to reduce the driving force. Will not be transmitted. Therefore, when the transfer paper 5 is pulled by hand in the front side direction D, the separating roller 8 also easily rotates with the rotation shaft 18 in the pulling direction, and both the sheet feeding roller 7 and the separating roller 8 are rotated. Therefore, the transfer paper 5 is easily rotated in the pulling-out direction. For this reason, a new release operation and a complicated release mechanism interlocked with the release operation are not required during the JAM processing, and the transfer paper 5 is not torn or torn in the middle as in the conventional case, so that the transfer paper 5 can be lightened easily. The transfer paper can be pulled out.

Next, two or more transfer sheets 5 are engaged between the sheet feeding roller 7a and the separating roller 8, and the separating roller 8 is moved with a slight torque to the sheet feeding side (a rotation direction opposite to the rotation direction B).
A so-called double feeding prevention mechanism in which two or more transfer sheets 5 are taken in the direction of arrow C inside the apparatus will be described.

When the separating roller 8 attempts to rotate in the sheet taking-in direction opposite to the rotating direction B during the double feeding, the rotation is transmitted to the rotating shaft 18 and further to the bearing 19 with a one-way gear. A one-way gear 19 (not shown) can transmit a rotational force from the rotating shaft 18 to the rotating shaft of the gear 22a. Further, the rotational force can transmit the driving force from the gear 22a to the gear 24b, but the rotational driving force of the motor 24B in the reverse rotation direction is transmitted to the gear 22a via the gear 24b, and the one-way The geared bearing 19 is in a locked state and is prevented from rotating in the paper feeding direction, so that the so-called double feeding problem is prevented.

In the first and second embodiments, the bearing 19 with the one-way gear is used as the driving force transmitting member. However, an angular spring in a predetermined direction may be used instead of the bearing 19.

[0050]

As described above, according to the present invention, a driving force transmitting member is provided in at least one of the driving force transmitting paths of the sheet feeding roller and the separating roller, and one of the driving forces is provided by the driving force transmitting member. Since the driving force can be transmitted in the force transmission direction and the rotation direction, and the idle rotation occurs in the other driving force transmission direction and the rotation direction, when the jammed paper is pulled from between the rollers, the paper feeding roller and the separating roller rotate easily. This makes it possible to easily and gently pull out the transfer paper without the need for a new release operation or a complicated release mechanism linked to the operation during the JAM processing, and to easily recover a paper jam or the like.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a first embodiment of an internal configuration of an image forming apparatus to which the present invention is applied.

FIG. 2 is a perspective view of a main part showing a schematic configuration of a manual paper feed unit in the image forming apparatus of FIG. 1;

FIG. 3 is a main part perspective view illustrating a schematic configuration of a manual sheet feeding unit in an image forming apparatus according to a second embodiment of the present invention.

FIG. 4 is a perspective view of a main part showing a schematic configuration of a sheet feeding device in a conventional image forming apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Apparatus main body 2 Paper supply part 7, 7a Paper supply roller 8 Separation roller 9 Mounting table 10, 10a Manual paper supply part 15 Side wall 16, 18, 23a Rotary shaft 17, 19 Bearing part 20 Torque limiter 21, 22, 22a Gear 23 Idle gear 24A, 24B Drive motor 24a, 24b Drive gear

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B65H 3/06 350 B65H 3/52 330 G03G 15/00 516

Claims (1)

(57) [Claims] 1. A sheet feeding roller for feeding a sheet, and separating rollers provided opposite to the sheet feeding roller and rotating in a direction opposite to the rotation direction of the sheet feeding roller. In the sheet feeding device for supplying a sheet, a driving force can be transmitted in one driving force transmitting direction and a rotating direction to a driving force transmitting path of the sheet feeding roller and the separating roller, and the other driving force transmitting direction and the other A driving force transmitting member that idles in the direction is provided, and the sheet feeding roller and the separating roller can be driven to rotate in respective predetermined rotation directions via the driving force transmitting member, and the sheet feeding roller is rotated by the predetermined rotation. A driving mechanism that rotates in the opposite direction to the separation roller and that can idle the separation roller in the predetermined rotation direction, wherein the driving mechanism part is configured such that the sheet feeding roller and the separation roller are separately driven by different driving sources. Yes, the time of the above-mentioned handling roller Sheet feeding apparatus in which the driving force transmitting member bearing portion of the shaft and the paper feed roller is characterized in that it is built.