JP2587655Y2 - Automatic 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 an automatic paper feeder used for a copying machine, a facsimile machine or a scanner.

[0002]

2. Description of the Related Art Conventionally, as this type of automatic paper feeder,
For example, Japanese Utility Model Publication No. 1-15855 (International Patent Classification B6)
As shown in 5H 3/06), a feed roller for feeding out the original from the platen at the time of forward rotation is supported by a drive shaft, and the forward rotation of the drive shaft is fed via a first one-way clutch. Some are configured to be transmitted to rollers.

In this conventional automatic paper feeder, in order to prevent double feeding of originals, a friction tongue is pressed against a paper feed roller, and the difference in friction coefficient between the paper feed roller, paper and the friction tongue is determined. This prevents the second or more originals from being fed out from the surface of the paper feed roller.

In this conventional automatic paper feeder, an auxiliary roller interlocking with the paper feed roller is used to feed the original on the document table between the paper feed roller and the friction tongue. The document is provided so as to contact the document on the document table from the same side as the paper feed roller.

If a plurality of originals or thin originals are placed on the original platen and the auxiliary rollers protrude from the upper surface of the original platen, the auxiliary rollers will block the original insertion path, making it impossible to reliably load the originals. There is fear.

In view of this, the auxiliary roller is supported on, for example, a drive shaft via a frame (or an arm) so as to be able to move up and down, and, for example, after a document is fed into a subsequent paper feeder for a predetermined time. , The reverse rotation of the drive shaft is transmitted to the frame via the second one-way clutch, and the auxiliary roller is retracted from the document insertion path of the document table.

In this conventional example, the exiting auxiliary roller is
When the next original is fed, the original moves to the original insertion path by the weight of the frame and the auxiliary roller.

In another conventional automatic sheet feeder shown in the side view of FIG. 5, the auxiliary roller 108 is configured to retreat below the document table 112, and the retracted auxiliary roller 108 is pushed into the path for inserting the document 115. For this purpose, a spring 111 for urging the frame 109 upward is provided.

In these conventional examples, when the original is inserted, the auxiliary roller 108 is withdrawn from the original insertion path on the original platen 112, so that the original 115 loaded on the original platen 112 is smoothly frictioned with the paper feed roller 101. The tongue piece 114 is pushed down to the point of contact.

[0010]

In these conventional automatic paper feeders, when a plurality of originals are strongly pushed in at the time of loading the originals, for example, as shown in FIG.
4 are pressed between the paper feed roller 101 and the friction tongue 114 to oppose the pressure of pressing the paper feed roller 4 against the paper feed roller 101, and the contact pressure between the originals 115 is increased. When the is rotated, the second or more originals 115 are fed out from the surface of the paper feed roller 101 together with the first original 115, and so-called double feeding may occur.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide an automatic paper feeder which can reliably prevent double feeding of originals with a simple configuration. .

[0012]

SUMMARY OF THE INVENTION According to the present invention, a paper feed roller for feeding out paper from a document table at the time of forward rotation, a friction tongue pressed by the paper feed roller, and a paper feed roller are supported. A drive shaft that is driven in the normal rotation direction via one one-way clutch, and is supported by the drive shaft via a frame so as to be able to enter and exit a document insertion path on a document table and is interlocked with the paper feed roller An auxiliary roller, moving means for moving the auxiliary roller into the document insertion path, and transmitting reverse rotation of the drive shaft to the frame against the moving means to move the auxiliary roller out of the document insertion path on the document table. In the automatic paper feeder provided with the second one-way clutch, the following measures are taken to achieve the above object. That is, it is rotatably supported by the drive shaft, moves in the reverse direction via the second one-way clutch when the drive shaft rotates in the reverse direction, and projects radially beyond the paper feed roller. A stopper for receiving the leading edge of the document on the auxiliary roller side with respect to the contact point is provided.

[0013]

In the present invention, for example, when the last document is sent out from the document table, the reverse rotation of the drive shaft is transmitted to the stopper by the second one-way clutch, and the stopper protrudes in the radial direction of the paper feed roller, and the friction tongue The leading edge of the document is received on the auxiliary roller side from the point of contact with the piece.

When the original is inserted into the original table, the leading end of the original is received by the stopper, but the forward rotation of the stopper is stopped by the drive shaft via the second one-way clutch.

In the present invention, in particular, a case where a detection means for detecting the presence or absence of a document on the document table is provided, and a drive control means for driving the drive shaft in the reverse direction when the detection means detects the document while the document is on standby is provided. In this case, a force can be applied from the drive shaft to the stopper to urge the stopper toward the auxiliary roller from the point of contact with the friction tongue, and the force for holding the leading end of the document at a predetermined position becomes stronger.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an automatic paper feeder according to an embodiment of the present invention will be specifically described with reference to the drawings.

This embodiment is an automatic paper feeder applied to, for example, an automatic document feeder for feeding and separating originals one by one to a copying machine. As shown in the configuration diagram of FIG. A paper roller 1, a drive shaft 2 rotatably supporting the paper feed roller 1, a first one-way clutch 3 for transmitting forward rotation of the moving shaft 2 to the paper feed roller 1, And a stepping motor 4 for switching and driving in the reverse direction.

When the drive shaft 2 is rotated forward by the stepping motor 4, the first one-way clutch 3 is engaged, the paper feed roller 1 rotates forward, and the original 6 placed on the original table 5 is fed. The sheet is fed out of the document table 5 by a frictional force with the roller 1 in the direction of a document conveying device (not shown) disposed on the left side of the drawing.

As shown in the side views of FIGS.
Above the paper feed roller 1, a friction tongue 8 pressed against the upper peripheral surface of the paper feed roller 1 by a spring 7 is arranged, and friction between the friction tongue 8 and the original 6 fed from the platen 5 is set. With the force, the second or more original 6 from the surface of the paper feed roller 1
The document 1 is fed out one by one in the direction of the document feeder.

The drive shaft 2 is rotatably supported at the distal ends of both side walls 9a of a frame 9 having left and right side walls 9a and a bottom wall 9b, and rotatably supported at the base ends of the both side walls 9a. A pair of auxiliary rollers 11 are coaxially fixed to the shaft 10.

The drive shaft 2 is provided with a second one-way clutch 12 for transmitting the reverse rotation of the drive shaft 2 to the frame 9.
Is driven in the reverse direction to retract the auxiliary roller 11 below the upper surface of the document table 5. When the drive shaft 2 rotates forward, the spring 13 pushes up the frame 9, and the auxiliary roller 11
Is projected into the document insertion path on the upper surface of the document table 5.

A drive gear 14 is rotatably supported on the drive shaft 2 so that forward rotation of the drive shaft 2 is transmitted to the drive gear 14 via a third one-way clutch 15. .

An intermediate gear 17 for interlocking the drive gear 14 with a driven gear 16 fixed to the shaft 10 is rotatably supported on the frame 9 so that the drive shaft 2 can be rotated forward. The feed roller 1 and the auxiliary roller 11 are both positive via the first one-way clutch 3, the drive shaft 2, the third one-way clutch 15, the drive gear 14, the intermediate gear 17, the driven gear 16, and the shaft 10. In the rolling direction, rotation is performed at substantially the same peripheral surface speed.

The second one-way clutch 12 is adapted to freely rotate the input side portion 18 fixed to the drive shaft 2 and the forward rotation of the drive shaft 2 and the input side portion 18 when the input side portion 18 rotates forward. When the drive shaft 2 and the input portion 18 rotate in the reverse direction following the forward rotation, the output portion 19 is engaged with the input portion 18 and driven in the reverse direction. A stopper 20 is provided integrally with the stopper 19.

The stopper 20 includes a stopper claw 21 projecting radially from the sheet feeding roller 1 and a restricted portion 22 formed in a partial annular shape along the side surface of the second one-way clutch 12 continuously with the stopper claw 21. Is provided.

As shown in FIGS. 1 to 4, the frame 9 has a restricting portion 23 formed by bending the front edge of one side wall 9a.

By receiving the reverse rotation side edge of the restricted portion 22 in the restriction portion 23, the rotation range of the stopper 20 in the reverse rotation direction is reduced as shown in the side views of FIGS. Reference numeral 21 is limited to an operation position located on the auxiliary roller 11 side of a point of contact between the paper feed roller 1 and the friction tongue 8 in the path of the document 6.

Further, by receiving the forward rotation side edge of the restricted portion 22 by the restriction portion 23, the rotation range of the stopper 20 in the normal rotation direction is reduced as shown in FIG.
Is limited to the release position located outside the passage of the document 6.

Further, in this embodiment, as shown in FIG. 1, a switch 2 for detecting a document 6 placed on a document table 5 is provided.
4 and a drive control device 25 are provided.
When the switch 24 detects the document 6, the drive control unit 25 excites the stepping motor 4 in the reverse direction to drive the drive shaft 2 in the reverse direction.

In this automatic paper feeder, for example, when the original 6 is sent out from the original table 5, the reverse rotation of the drive shaft 2 is transmitted to the stopper 20 via the second one-way clutch 12, and the stopper 20 is fed. The stopper claw 21 projecting in the radial direction of the paper roller 2 advances toward the auxiliary roller 11 side from the contact point between the friction tongue 8 and the paper feed roller 1, and the frame 9 swings downward and the auxiliary roller 11 Retreats below the upper surface of the document table 5.

Accordingly, the document 6 is inserted into the document table 5 without being hindered by the auxiliary roller 11, and the leading end thereof is received by the stopper 20.

When the original 6 is loaded on the original table 5, the original is in a standby state. When the original 6 inserted into the original table 6 is detected by the switch 24, the stepping motor 4 is excited in the reverse direction. As shown in FIG. 2, the stopper 20 and the frame 9 are urged in the reverse direction against the spring 13, and the stopper claw 21 strongly stops the leading end of the document 6. This prevents the document 6 from forcibly moving the stopper claw 21 in the forward rotation direction even when the document 6 is strongly pressed, and the leading end of the document 6 is positioned between the paper feed roller 1 and the friction tongue 8. Is prevented from being pushed.

At the time of feeding the original, the stepping motor 4 is driven in the forward direction, and the stopper 20 can rotate in the forward direction following the forward rotation of the drive shaft.
For example, as shown in FIGS. 3 and 4, the frame 9 is raised by the spring 13, and the auxiliary roller 11 projects above the upper surface of the document table 5.

The forward rotation of the drive shaft 2 is transmitted to the auxiliary roller 11 via the third one-way clutch 15.
The document 6 is fed by the auxiliary roller 11 toward a contact point between the paper feed roller 1 and the friction tongue 8.

Therefore, the original 6 is not strongly pushed into the contact point between the paper feed roller 1 and the friction tongue 8,
The document 6 is fed by the frictional force between the auxiliary roller 11 and the lowermost document 6, and the friction tongue 8 may be lifted more than necessary against the spring 7 as shown in FIG. As a result, the originals 6 reliably pass between the paper feed roller 1 and the friction tongue 8 one by one, and the occurrence of double feeding is reliably prevented.

In this embodiment, the second one-way clutch 12 for transmitting the reverse rotation of the drive shaft 2 to the frame 9 is also used as the one-way clutch for transmitting the reverse rotation of the drive shaft 2 to the stopper 20. , Simple in configuration, easy and
It can be implemented at low cost.

Further, in the above-described embodiment, it is possible to form the stopper 20 separately from the output portion 19 of the second one-way clutch 12, but as in the above-described embodiment, the stopper 20 can be formed. If the output side portion 19 of the second one-way clutch 12 and the second one-way clutch 12 are integrally formed, the number of parts does not need to be increased, which is advantageous in reducing costs.

In the above-described embodiment, the stepping motor 4 is excited in the reverse direction when the original 6 is on the original platen 5. However, the stepping motor 4 is simply stopped when the original is on standby and the stepping motor 4 is stopped. The stopper 20 via the drive shaft 2 and the second one-way clutch 12
The same effect can be obtained by receiving a force that attempts to move the in the normal rotation direction.

In the example described above, the present invention has been described by taking as an example a paper automatic supply device applied to an automatic document supply device for separating and supplying originals one by one to a copying machine.
The present invention is not limited to this embodiment, but an automatic document feeder for feeding and separating originals one by one to a facsimile machine and a scanner, and a recording paper for feeding and feeding one by one to a copier and a scanner. The present invention can also be applied to a paper supply device that performs the above.

[0040]

As described above, according to the present invention, when the drive shaft rotates in the reverse direction, the auxiliary roller is moved in the reverse direction in conjunction with the drive shaft via the second one-way clutch for raising and lowering the auxiliary roller. A stopper is provided that protrudes radially beyond the paper roller and receives the leading edge of the document on the auxiliary roller side beyond the point of contact between the paper feed roller and the friction tongue. Is strongly received by the stopper on the auxiliary roller side with respect to the contact point, and it is possible to prevent a plurality of papers from being pushed into the contact point between the paper feed roller and the friction tongue. Supply can be prevented.

Further, since it is only necessary to add a stopper to the structure of the conventional example, the structure is simple, and it can be implemented easily and inexpensively.

In the present invention, in particular, a case where a detection means for detecting the presence or absence of a document on the document table is provided, and drive control means for driving the drive shaft in the reverse direction when the detection means detects the document while the document is on standby is provided. Since the limiting force of the stopper that limits the pushing of the original can be increased, it is possible to reliably prevent a plurality of sheets from being pushed into the contact point between the feed roller and the friction tongue. Thus, it is possible to reliably prevent a plurality of sheets from being supplied simultaneously.

[Brief description of the drawings]

FIG. 1 is a plan view of an embodiment of the present invention.

FIG. 2 is a side view of the embodiment of the present invention when the drive shaft is reversed.

FIG. 3 is a side view of the embodiment of the present invention at the start of forward rotation of the drive shaft.

FIG. 4 is a side view of the embodiment of the present invention during forward rotation of the drive shaft.

FIG. 5 is an explanatory diagram of a problem to be solved by the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 paper feed roller 2 drive shaft 3 first one-way clutch 5 document table 6 document 8 friction tongue 9 frame 11 auxiliary roller 12 second one-way clutch 13 spring 20 stopper 24 switch 25 drive control device

──────────────────────────────────────────────────続 き Continuing on the front page (72) Toshiyuki Watanabe 2-18-18 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Yuzo Morimoto 2-18-18 Keihanhondori, Moriguchi-shi, Osaka (58) Field surveyed (Int. Cl. ⁶ , DB name) B65H 1/00-3/68

Claims (2)

(57) [Scope of request for utility model registration] A feed roller that feeds a sheet from a document table during forward rotation; a friction tongue pressed by the feed roller; and a supporter for the feed roller, and a first one-way clutch. A drive shaft that is driven in the forward rotation direction, an auxiliary roller that is supported by the drive shaft via a frame so as to be able to enter and exit a document insertion path on a document table, and that is interlocked with the paper feed roller; A moving means for moving the original into the original insertion path, and a second one-way clutch for transmitting the reverse rotation of the drive shaft to the frame against the moving means and for retracting the auxiliary roller from the original insertion path on the original table. In the automatic paper feeder provided, when the drive shaft is rotatably supported and moves in the reverse direction via the second one-way clutch when the drive shaft rotates in the reverse direction, it protrudes radially beyond the paper feed roller to feed the paper. Point of contact between roller and friction tongue Automatic sheet feeding device and providing a stopper to receive the leading end of the document at the remote auxiliary roller. 2. A method according to claim 1, further comprising: detecting means for detecting the presence or absence of a document on the document table; and driving control means for driving the drive shaft in a reverse direction when the detecting means detects the document while the document is on standby. The automatic sheet feeding device according to claim 1.