JP2002087619A - Automatic paper feeding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic paper feeding device not causing non-feeding of a medium or overlap feeding. SOLUTION: A friction material 13 is movably provided. A link mechanism is provided for keeping constant the approach angle of an end part of a medium 3 relative to a contact surface of the friction material 13 by moving the friction material 13 interlocking with the turning motion of a medium receiver 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic sheet feeding apparatus which is mounted on an image forming apparatus, sequentially feeds out media loaded in the apparatus, and feeds the medium into the image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, an automatic paper feeder is mounted on an image forming apparatus such as a page printer, a copying machine, and a facsimile machine in an electrophotographic recording apparatus or an electrostatic recording apparatus. This automatic paper feeder sequentially feeds out a large number of recording media or originals (hereinafter, referred to as a medium) stacked in the device, separates them one by one, and feeds them into the image forming apparatus. In this automatic paper feeder, a paper feed roller for feeding out a medium loaded on a medium receiver rotatably provided in the apparatus to a transport path in the image forming apparatus is provided. A separation piece provided with a friction material that comes into contact with the paper feed roller is provided. The medium fed by the paper feed roller is fed to the transport path through the space between the paper feed roller and the separation piece. However, when a plurality of papers are fed, the medium is separated by the separation piece into one sheet. The uppermost sheet is fed to the transport path.

A medium loaded in the automatic paper feeder is loaded in a medium cassette detachably provided in the automatic paper feeder. When the media cassette loaded with the media is mounted on the automatic paper feeder, the movable media receiver provided in the media cassette pushes up the media by a spring or the like, and the leading end of the media is fed to the paper feed roller. Contact. Then, in this state, the paper feed roller rotates, and the medium is fed to the transport path in the image forming apparatus.

A movable medium receiver having a fulcrum at one end and a friction piece at the other end is often used.

[0005]

In a conventional automatic paper feeder, a medium fed by a paper feed roller is separated into one by a friction material provided on a separation piece. If the entrance angle of the leading end of the medium with respect to the contact surface with the paper roller is too large, the medium cannot be fed any further and non-feeding occurs. On the other hand, if the angle of entry of the leading end of the medium with respect to the contact surface of the friction material is too small, double feeding occurs. Therefore, it is desirable that the approach angle of the leading end of the medium with respect to the contact surface of the friction material is always constant.

However, when an automatic paper feeder is provided with a movable medium receiver having a fulcrum at one end and a medium is loaded on the medium receiver, friction is generated according to the amount of the medium loaded on the medium receiver. There has been a problem that the angle of entry of the leading end of the medium with respect to the contact surface of the material changes.

The approach angle of the leading end of the medium with respect to the contact surface of the friction material is larger when the number of the media loaded on the medium receiver is larger than when the number of the media is smaller, and the friction material is shifted from the rotation fulcrum of the medium receiver. It becomes larger as the distance to is shorter.

[0008] Further, the wear angle of the rubber roller and the friction material of the paper feed roller with time also changes the direction in which the leading angle of the leading end of the medium with respect to the contact surface of the friction material increases.

For the above reason, there is a problem that when the leading end of the medium enters the contact surface of the friction material at a large angle, the medium is not fed.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a medium loaded on a medium loading plate which has a fulcrum on a side opposite to a medium feeding side and rotates according to a loaded amount. When feeding multiple sheets sequentially with the paper feed roller,
In an automatic paper feeder which separates and feeds the sheet by a friction member provided in contact with the paper feed roller, the friction member is movably provided, and the friction is interlocked with the rotation amount of the medium loading plate. A link mechanism is provided for moving the member and maintaining a constant angle of entry of the leading end of the medium with respect to the contact surface of the friction member.

According to the above configuration, since the friction member moves in accordance with the amount of the medium loaded on the medium loading plate, the angle of entry of the leading end of the medium with respect to the contact surface of the friction member is kept constant regardless of the amount of the medium loaded. Can be kept. Therefore, it is possible to maintain the optimum angle at which the medium enters without causing non-feeding or double feeding.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. Elements common to the drawings are assigned the same reference numerals.

[0013] First Embodiment FIG. 1 explanatory view showing the structure of an automatic feeder of the first embodiment, FIG. 2 is a partial sectional view showing an automatic sheet feeding device of the first embodiment, FIG. 3 is an explanatory diagram showing the structure of the automatic sheet feeding device according to the first embodiment.

An automatic paper feeder is mounted on an image forming apparatus such as a page printer, a copying machine, and a facsimile machine in an electrophotographic recording apparatus or an electrostatic recording apparatus. This automatic paper feeder sequentially feeds out a large number of recording media or originals (hereinafter, referred to as a medium) stacked in the device, separates them one by one, and feeds them into the image forming apparatus. Hereinafter, the structure of the automatic sheet feeder will be described.

1, 2 and 3, the automatic paper feeder 1 is entirely covered by a frame (not shown). A media cassette 2 is detachably mounted on the automatic paper feeder 1. The medium cassette 2 is provided with a medium receiver 4 which is a medium stacking plate on which the medium 3 is stacked. The medium receiver 4 is attached to one end of a shaft 28, and the medium receiver 4 rotates around the shaft 28 provided on the side opposite to the medium feeding side. The other end of the shaft 28 is supported by the frame 20 of the medium cassette 2. A friction material 5 is provided on the end of the medium receiver 4.

One end of a hopper 6 is in contact with the bottom of the medium cassette 2. The other end of the hopper 6 has a shaft 7
Is mounted, and the hopper 6 rotates about the shaft 7 as a fulcrum. Both ends of the shaft 7 are freely rotatably inserted into the frame 20 of the medium cassette 2 and are supported by the frame 20. A gear 8 is attached to the shaft 7.

One end of the hopper 6 has a spring 9 attached to the frame 20 of the medium cassette 2 at one end.
The other end of the hopper 6 is attached, and one end of the hopper 6 is pushed up by a biasing force of the spring 9 in a direction in which the medium 3 comes into contact with a feed roller described later.

A frame (not shown) of the automatic paper feeder 1 includes:
Both ends of a shaft 11 to which the paper feed roller 10 is attached are freely rotatably inserted, and this shaft 11 is supported by a frame of the automatic paper feeder 1. The paper feed roller 10 has a one-way clutch and is rotatable only in the direction of arrow M. The paper feed roller 10 has a rubber roller 10
a. Further, a friction material 13 which is a friction member provided on the separation piece 12 is in contact with the rubber roller 10a of the paper feed roller 10. The shaft 1 is located on both lower portions of the separation piece 12
4 (14a, 14b) is attached to one end,
The other ends of the shafts 14a and 14b are connected to a link 17 (17a,
17b). Thus, the angle of the friction material 13 with respect to the horizontal plane (the bottom surface of the medium cassette 2) can be made variable. The other end of a spring 16 whose one end is attached to the frame 20 of the medium cassette 2 is attached to the bottom surface of the separation piece 12, and the urging force of this spring 16 presses the friction material 13 against the paper feed roller 10. Have been.

As shown in FIG.
One end of (18a, 18b) is attached, and a link 17 (17a, 18b) is
17b) rotates. The other ends of the shafts 18a and 18b are rotatably inserted into the frame 20 of the medium cassette 2 so as to be freely rotatable.
8b) is supported.

Further, a gear portion 19 is formed in a part of the link 17, and the gear portion 19 meshes with the gear 8.

The hopper 6, the gear 8, the spring 9, the separating piece 12, the spring 16, and the link 17 constitute a link mechanism.

Next, the operation of the friction material 13 during the medium feeding operation of the automatic sheet feeding apparatus 1 having the above configuration will be described.

In FIG. 1, when the medium 3 is stacked on the medium receiver 4, if the number of stacked sheets is large, the hopper 6 rotates in the direction of arrow F against the urging force of the spring 9, and moves downward. As a result, the gear 8 rotates in the direction of arrow H. By this rotation, the links 17a and 17b provided with the gear portion 19 meshing with the gear 8 rotate in the direction of arrow A about the shaft 18 as a fulcrum. The rotation of the links 17a and 17b causes the shaft 1 to rotate.
4a and 14b move in the direction of arrow A with the shaft 18 as a fulcrum, so that the separation piece 12
It rotates in the direction of arrow D about the point of contact with zero. As a result, the end 13a of the friction material 13 rotates in a direction approaching the paper feed roller 10, and the angle of entry θ1 of the leading end of the medium 2 with respect to the contact surface of the friction material 13 with the rubber roller 10a of the paper feed roller 10 is reduced. Become.

On the other hand, the medium 3 is fed out and the medium cassette 2
When the number of the media 3 in the inside decreases, the media receiver 4
It pivots in the direction of arrow L shown in FIG. Then, the hopper 6 rotates in the direction of arrow G by the urging force of the spring 9 and moves upward, whereby the gear 8 rotates in the direction of arrow N. The links 17a and 17b having the gear portion 19 meshing with the gear 8 by this rotation
Is rotated in the direction of arrow B with the fulcrum as a fulcrum. This link 17
The shafts 14a and 14b move in the direction of arrow B around the shaft 18 by the rotation of the shafts a and 17b, whereby the separation piece 12 rotates in the direction of arrow P about the contact point between the friction material 13 and the paper feed roller 10. Move. Thereby, the end 13 of the friction material 13
a rotates in a direction away from the paper feed roller 10 and the friction material 1
The approach angle θ2 of the leading end of the medium 2 with respect to the contact surface 3 increases. Then, the position of the shaft 18 serving as the fulcrum of the link 17 and the gear ratio are set so that the above θ1 and θ2 become equal.

Next, the paper feed operation of the automatic paper feeder 1 will be described.

When the automatic paper feeder 1 receives a paper feed command from a higher-level device (not shown), a control unit (not shown) of the automatic paper feeder 1 drives a drive source (not shown) to turn the paper feed roller 10 into an arrow. Rotate in M direction. Thereby, the plurality of media 3 on the upper surface are sent to the separation piece 12. Then, only the uppermost one of the plurality of media 3 is separated by the friction material 13 provided on the separation piece 12 and fed out of the media cassette 2.
Thereafter, the medium 2 fed into the image forming apparatus (not shown) is started to be conveyed by a conveying roller (not shown) inside the image forming apparatus.

When the medium 3 has been fed to a predetermined position, the control unit stops the rotation of the paper feed roller 10. However, since the paper feed roller 10 has a one-way clutch, it pulls the medium 3 to be fed. And continue rotating in the direction of arrow M. Then, when the rear end of the medium 3 comes off the friction material 13, the rotation of the paper feed roller 10 stops.

Then, when the paper feed roller 10 starts rotating again by the control unit, the next medium 3 is similarly fed from the automatic paper feeder 1 into the image forming apparatus (not shown).

As described above, in the first embodiment, the entry angle of the leading end of the medium 3 with respect to the contact surface of the friction material 13 can be kept constant regardless of the loading amount of the medium 2 on the medium receiver 4. Optimum medium 2 that does not cause non-feed or double feed
Can be maintained. As a result, the medium 2 can always be fed, and the reliability of the sheet feeding performance can be improved.

Second Embodiment Next, a second embodiment will be described. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. FIG. 4 is an explanatory diagram showing the structure of the automatic paper feeder according to the second embodiment.

In FIG. 4, one end of a medium remaining amount detecting lever 21 is integrally attached to a shaft 8 provided in the automatic sheet feeding device 22. Accordingly, the medium remaining amount detecting lever 21 operates integrally with the hopper 6, and when the number of the mediums 3 on the medium receiver 4 is large, the hopper 6 is positioned at the position indicated by the solid line. The detection lever 21 is positioned at a position indicated by a solid line. On the other hand, when the number of media on the medium receiver 4 is small, the hopper 6 is positioned at the position indicated by the broken line,
1 is positioned at the position indicated by the broken line. A portion of the frame 30 of the medium cassette 29 corresponding to the medium remaining amount detection lever 21 is cut out, and the position of the end of the medium remaining amount detection lever 21 can be seen from the cut out portion from the outside. I can do it.

Next, a description will be given of a medium feeding operation of the automatic sheet feeding device 22 having the above configuration. Here, only the operation of the medium remaining amount detection lever 21 that changes according to the number of the media 3 on the medium receiver 4 and the remaining amount detection method will be described.

When the medium 3 is stacked on the medium receiver 4, if the number of stacked sheets is large, the hopper 6 pivots in the direction of arrow F against the urging force of the spring 9 and moves downward as indicated by the solid line. Then, the medium remaining amount detection lever 21 rotates in the direction of arrow Q and moves up to the position shown by the solid line. Thus, by looking at the medium remaining amount detection lever 21 from the cutout portion of the frame 30 of the medium cassette 29, it can be seen that the amount of the medium 3 stacked on the medium receiver 4 is large.

On the other hand, the medium 3 is fed out and the medium cassette 2
When the number of the media 3 in the media 9 decreases, the media receiver 4 rotates around the shaft 28 in the direction of the arrow L and rises. Then, the hopper 6 is rotated in the direction of arrow G by the urging force of the spring 9 and rises, and the medium remaining amount detection lever 21 is moved by the arrow R
In the direction shown in FIG. Accordingly, by looking at the medium remaining amount detection lever 21 from the cutout portion of the frame 30 of the medium cassette 29, it can be seen that the amount of the medium 3 stacked on the medium receiver 4 is small.

The other operations are the same as those in the first embodiment, and the description is omitted.

As described above, in the second embodiment, the same effects as those of the first embodiment can be obtained, and the remaining amount detecting lever 21 is provided integrally with the hopper 6, so that the remaining amount can be reduced when the hopper 6 is manufactured. The quantity detection lever 21 can be manufactured together. Therefore, the number of components can be reduced as compared with the case where the remaining amount detection lever 21 is provided as a separate member, and the number of manufacturing steps is also reduced.

Third Embodiment Next, a third embodiment will be described. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 5 is an explanatory view showing a part of the configuration of an automatic sheet feeder according to the third embodiment, FIGS. 6 and 7 are sectional views showing a gear bearing according to the third embodiment, and FIG. FIG. 11 is an explanatory diagram illustrating a configuration of a part of the automatic sheet feeding apparatus according to a third embodiment.

In FIG. 5, the rubber roller 10a and the friction material 13 of the paper feed roller 10 are in a worn state.
The positional relationship between the friction material 13 and the paper feed roller 10 at that time is shown. When the rubber roller 10a of the paper feed roller 10 and the friction material 13 are worn, the separation piece 12 rotates around the shaft 14 in the direction of arrow P. Thereby, the approach angle θ3 of the leading end of the medium 2 with respect to the contact surface of the friction material 13 becomes larger than θ1 shown in FIG.

Therefore, in the automatic paper feeder 36 of the present embodiment, the bearing 24 of the gear 8 shown in FIG. 6 is movably held in a holding portion 32 formed integrally with the medium cassette 27. The bearing 24 has a hole formed therein, and the shaft 7 to which the gear 8 is attached is fitted into the hole. Therefore, the gear 8 can also move in the direction of the arrow ST along with the movement of the bearing 24 in the direction of the arrow ST. A push button 25 is provided integrally with the bearing 24. A part of the frame 27 of the medium cassette 26 is cut out, and the operator can touch the push button 25 from the cutout.

One end of a spring 31 is attached to an end of the bearing 24 opposite to the push button 25 side. The other end of the spring 31 is attached to a side wall of the holding section 32. The bearing 24 is pressed in the direction of arrow T by the urging force of the spring 31. Note that the bearing 24 does not protrude outside the holding part 32 by the end part 24 a shown in FIG. 7 abutting on the end part 32 a of the holding part 32.

The push button 25 is connected to the spring 31
5 and 6 is moved from the position shown in FIGS. 5 and 6 to the position shown in FIGS. 7 and 8. Thus, the bearing 24 moves in the direction of the arrow S, and the gear 8 can be moved in the direction of the arrow S shown in FIG.

The bearing 24 is provided with a hook portion 33, which hooks and locks a locking portion described later. A locking bar 34 is provided inside the holding portion 32, and a locking portion 35 is formed at an end of the locking bar 34. Then, the locking portion 35 is hooked on the hook portion 33 as shown in FIG. 7, whereby the bearing 24 is held at the position shown in FIG. 7 against the urging force of the spring 31.

The shaft 7, the gear 8, the separation piece 12
, The link 17 and the push button 25 constitute an adjusting means.

Next, a description will be given of a medium feeding operation of the automatic sheet feeding device 36 having the above configuration. Here, only the operation of changing the entry angle of the leading end of the medium 3 with respect to the contact surface of the friction material 13 by the operation of the operator will be described.

When the rubber roller 10a and the friction material 13 of the paper feed roller 10 are worn, the operator presses the push button 24.
To change from the position shown in FIGS. 5 and 6 to the position shown in FIGS. Then, the bearing 24 moves the arrow S by the stroke d which is pushed in against the urging force of the spring 31.
In the direction, the hooking portion 33 hooks and locks the locking portion 35, and the bearing 24 is held at the position shown in FIG. By the movement of the push button 24, the gear 8 moves by the stroke d in the direction of the arrow S.

Then, the links 17a, 17b having the gear portions 19 meshing with the gear 8 by the movement of the gear 8
Rotates about the shaft 18 in the direction of arrow A. Due to the rotation of the links 17a and 17b, the shafts 14a and 14b
8 is used as a fulcrum to move in the direction of arrow A, whereby the separation piece 12 rotates in the direction of arrow D about the contact point between the friction material 13 and the paper feed roller 10. As a result, the end 13a of the friction material 13 rotates in a direction approaching the paper feed roller 10, and the approach angle θ4 of the leading end of the medium 2 with respect to the contact surface of the friction material 13
Is smaller than θ3 shown in FIG.

In order to return the bearing 24 from the position shown in FIG. 7 to the position shown in FIG. 6, if the push button 25 is pressed again in the direction of arrow S, the locking portion 34 comes off the hooking portion 33, and the spring Due to the urging force of 31, the bearing 24 returns to the position where the end 24a contacts the end 32a of the holding portion 32.

The other operations are the same as those in the first embodiment, and the description is omitted.

In the third embodiment, the same effects as those of the first embodiment can be obtained, and the rubber roller 10a of the paper feed roller 10 and the friction material 13 are worn over time, and the friction material Medium 3 against 13 contact surfaces
When the angle of entry of the tip of the member becomes larger than that in a state where it is not worn, the separating piece 12 is rotated to
Can be returned to the angle at which the rubber roller 10a and the friction material 13 of the paper feed roller 10 are not worn out. Therefore, the rubber roller 10a and the friction material 13 of the paper feed roller 10 can be used for a long time. As a result, non-feeding of the medium 3 does not occur, and the medium 3 can always be fed.

[0051]

As described above in detail, according to the present invention, the friction member is provided so as to be movable, and the friction member is moved in conjunction with the amount of rotation of the medium loading plate, so that the medium contacts the contact surface of the friction member. By providing a link mechanism for keeping the entrance angle of the leading end constant, it is possible to always feed the medium, and it is possible to improve the reliability of the sheet feeding performance.

Further, even if the friction member is provided so as to be movable, and the adjusting means for setting the angle of entry of the leading end of the medium with respect to the contact surface of the friction member to a predetermined angle is provided, non-feeding of the medium does not occur. Thus, the medium can always be fed.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating a structure of an automatic sheet feeder according to a first embodiment.

FIG. 2 is a partial cross-sectional view illustrating the automatic sheet feeder according to the first embodiment.

FIG. 3 is an explanatory diagram illustrating a structure of the automatic sheet feeder according to the first embodiment.

FIG. 4 is an explanatory diagram illustrating a structure of an automatic sheet feeder according to a second embodiment.

FIG. 5 is an explanatory diagram illustrating a configuration of a part of an automatic sheet feeding apparatus according to a third embodiment.

FIG. 6 is a sectional view showing a gear bearing according to a third embodiment.

FIG. 7 is a sectional view showing a gear bearing according to a third embodiment.

FIG. 8 is an explanatory diagram illustrating a configuration of a part of an automatic sheet feeding apparatus according to a third embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Automatic paper feeder 3 Medium 4 Medium receiver 6 Hopper 10 Paper feed roller 12 Separation piece 13 Friction material 17 Link 21 Remaining medium detection lever 22 Automatic paper feeder 25 Push button 36 Automatic paper feeder

Claims (5)

[Claims] 1. A fulcrum is provided on a side opposite to a medium feeding side,
The media loaded on the media loading plate that rotates according to the loading amount is sequentially fed by a feed roller, and when a plurality of media are fed, a friction member provided in contact with the feed roller is used to feed the media.
In the automatic sheet feeder that separates and feeds the sheet, the friction member is movably provided, and the friction member is moved in conjunction with a rotation amount of the medium stacking plate, and a leading end of the medium with respect to a contact surface of the friction member. An automatic sheet feeder, characterized in that a link mechanism is provided for keeping the entrance angle of the section constant. 2. The separation member, wherein the friction member is provided on a separation piece, and the link mechanism includes a hopper that partially contacts the medium loading plate and rotates with the rotation of the medium loading plate; And a link member connected to the hopper and moving the separation piece by an amount corresponding to the amount of rotation of the hopper to maintain a constant angle of entry of the leading end of the medium with respect to the contact surface of the friction member. The automatic sheet feeding device according to claim 1. 3. A medium remaining amount detection lever that operates integrally with the hopper, rotates by an amount corresponding to the amount of rotation of the medium stacking plate, and indicates a medium stacking amount on the medium stacking plate. 2. The automatic paper feeder according to 2. 4. A fulcrum is provided on the side opposite to the medium feeding side,
The media loaded on the media loading plate that rotates according to the loading amount is sequentially fed by a feed roller, and when a plurality of media are fed, a friction member provided in contact with the feed roller is used to feed the media.
In the automatic sheet feeder that separates and feeds the sheet, the friction member is movably provided, and an adjusting means for setting a leading angle of the leading end of the medium to a contact surface of the friction member with a predetermined angle is provided. Automatic paper feeder featured. 5. The friction member is provided on a separation piece, and the adjusting means is connected to the separation piece, and a link member that moves the separation piece by rotating, and is connected to the link member and pressed. A push button for rotating the link member. When the push button is pressed, the link member rotates, and the separation piece moves in conjunction with the rotation of the link member. ,
5. The automatic paper feeder according to claim 4, wherein the angle of entry of the leading end of the medium with respect to the contact surface of the friction member is a predetermined angle.