JP2003280294A - Original transport device and multi-function machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent paper jamming caused by the collision of the leading end of an original with the trailing end of the same one on a transport path in the case of transporting the both-face original having a long original length. <P>SOLUTION: The original transport device is provided with: a transport path 411 for transporting the original placed on an original platen 301 to a reading point (mirror) 312; a 1st reversion path 412 for discharging the trailing end of the original which is transported with the leading end first and changing the carrying direction by reversing the rotating direction of a roller; a 2nd transport path 413 for transporting the original from the 1st transport path 411 to the 1st reversion path 412; a 3rd transport path 414 for returning the original with the 1st face already read from the 1st reversing path 412 to the 1st transport path 411; a 2nd reversion path 415 for discharging the original with the 2nd surface already read from the 1st reversion path 412 after turning the original upside down; and a control means which, when it is judged that the trailing end of the original lies on the 1st reversion path 412 when it is detected that the leading end of the same original whose 2nd face is already read enters the 1st reversion path 412, separates a follower roller 318 on the 1st reversion path 412 from the original. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document feeding device having a feeding path for reversing the reading surface of a double-sided document and a multifunction machine using the same.

[0002]

2. Description of the Related Art In recent years, multifunctional machines have been introduced which realize a plurality of functions such as a copy function, a FAX function and a printer function by one unit. Some of this type of multi-function peripherals are equipped with a document transport device having a transport path for reading double-sided documents.

Conventionally, this type of document conveying apparatus has a complicated conveying path because it includes an inversion path. Specifically, there are two inversion paths in the conveyance path. That is, the first is a first reversing path for reversing the reading surface of a double-sided original, and the second is a second reversing path for correcting the order of discharged originals in the original order. Without this second reversal path, the originals are placed on the discharge tray with the back side of page 1, the front side of page 1, the back side of page 2, and the front side of page 2. Will be discharged. As described above, since the two inversion paths are provided, the transport path is complicated.

Specifically, as shown in FIG. 19, a first conveying path 1903 from a document table 1901 to a reading point 1902.
In addition, it has a second conveyance path 1905 for conveying the manuscript whose first surface has been read from the reading point 1902 to the first reversing path 1904. By switching back the original in the first transport path 1903, the first reverse path 1 is set with the rear end of the original when inserted in the first reverse path 1904 as the leading end.
Discharge from 904. There is a third conveyance path 1906 for returning the original from the first reversal path 1904 to the first conveyance path 1903, and again the second surface of the original is conveyed to the reading point 1902 via the first conveyance path 1903, and the second conveyance path 1903 is provided. The document whose second surface has been read is returned to the first inversion path 1904 via the conveyance path 1905.

The document is switched back on the first reversing path 1904, but this time, the document is conveyed to the first reversing path 190.
The transport destination is switched from No. 4 to the second inversion path 1907. Second
The reversing path 1907 is a U-shaped curved path, and the front and back surfaces of the document are reversed by this path and the document is ejected to the ejection table 1908.

As described above, in the document feeding device, in the first reversing path 1904, depending on whether the document to be inserted is a document whose first surface has been read or a document whose second surface has been read, the discharge destination is set. Are switching.

[0007]

However, in the conventional document conveying apparatus, when a double-sided document having a long document length is conveyed,
In the first reversing path 1904, there arises a problem that the leading edge and the trailing edge of the same document collide with each other.

That is, the document whose first side has been read enters the first inversion path 1904, and the trailing edge of the document is placed in the first inversion path 190.
When the number reaches 4, the sheet is discharged to the third transport path 1906 with the trailing edge of the original as the leading edge by switchback.

When the leading edge of the document whose second side has been read enters the first reversing path 1904 again, if the document length is long, the trailing edge of the same document may not have passed through the first reversing path 1904. Occurs.

In this case, the rollers of the first reversing path 1904 are rotating in the direction of discharging the original document to the third conveying path 1906, and this rotation direction is the rotation direction in which the leading edge of the original document entering the first reversing path 1904 is received again. Is the opposite direction.

Therefore, when the leading edge of the document is conveyed toward the first reversing path 1904 in this state, the first reversing path 1
At 904, the leading edge of the document is obstructed from proceeding, and nevertheless, the document continues to be conveyed.
There is a problem that the document is jammed in 04 and a paper jam occurs.

The present invention has been made in view of the above problems, and when a double-sided original having a long original is conveyed,
An object of the present invention is to provide an original document conveying device capable of preventing a paper jam due to the front end and the rear end of the same original document colliding on the conveying path, and a multifunction machine using the same.

[0013]

SUMMARY OF THE INVENTION According to the present invention, a first conveying path for conveying an original on a platen to a reading point and an original conveyed from the front end by reversing the rotation direction of a roller are discharged from the rear end. The first reversing path for changing the conveying direction, the second conveying path for conveying the first reversing path to the first reversing path, and the first document whose first surface has been read from the first reversing path for the first reversing path. The third conveyance path for returning to the conveyance path, the second reversal path for inverting and discharging the front and back of the document whose second surface has been read from the first reversal path, and the leading edge of the document for which the second surface has been read are When it is detected that the sheet enters the first inversion path, the trailing edge of the same document is the first
When it is determined that the roller exists in the reverse path, the roller in the first reverse path is separated from the original.

Accordingly, even when a double-sided original having a long original length is conveyed, the roller of the first reversing path does not prevent the leading edge of the original from entering the first reversing path, and therefore, the first reversing path does not have to move. It is possible to prevent a situation in which the document is prevented from proceeding, the document is jammed in the first inversion path, and a paper jam occurs.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION A document conveying apparatus according to a first aspect of the present invention conveys a document on a platen from a leading end by reversing a rotation direction of a roller and a first conveying path for conveying a document to a reading point. First change the transport direction by ejecting the printed document from the rear edge
An inversion path, a second transportation path for transporting from the first transportation path to the first inversion path, and a third transportation path for returning a document whose first surface has been read from the first inversion path to the first transportation path. And a second reversing path for reversing and discharging the front and back of the document whose second surface has been read from the first reversing path, and a leading edge of the document whose second surface has been read enters the first reversing path. When it is determined that the trailing edge of the same document is present in the first reversing path in the case of detection, control means for separating the roller of the first reversing path from the document is adopted.

According to this structure, when it is detected that the leading edge of the document whose second surface has been read enters the first reversing path,
If it is determined that the trailing edge of the same document exists in the first inversion path,
The roller of the first inversion path is separated from the original. As a result, even when a double-sided original having a long original length is conveyed, the rollers of the first reversing path do not prevent the leading edge of the original from entering the first reversing path. It is possible to avoid a situation in which the progress is hindered, the original is jammed in the first reverse path, and a paper jam occurs.

According to a second aspect of the present invention, in the document conveying apparatus according to the first aspect, the controller determines that the length of the document is measured by a sensor on the conveying path and whether the measured value exceeds a set value. The configuration is performed based on whether or not.

According to this structure, it is determined whether or not the roller on the first reversing path should be separated from the original based on the actual length of the original conveyed on the conveying path. As a result, the roller is not moved when the document length is shorter than the set value, and the roller is moved only when the document length is longer than the set value. Therefore, the roller should be moved only when it is necessary to actually move it. It is possible to minimize the generation of noise due to the movement of the roller. Also, the current consumption for moving the roller can be minimized.

According to a third aspect of the present invention, in the document feeder according to the first aspect, the control means makes a determination based on whether or not the size of the document set on the document table exceeds a set value. Take the composition.

According to this structure, it is determined whether or not the roller of the first reverse path should be separated from the original based on the size of the original set on the original table. As a result, if the document size is smaller than the set value, do not move the roller,
Since the roller is moved only when the document size is longer than the set value, the roller can be moved only when it is necessary to actually move it, and the generation of abnormal noise due to the movement of the roller can be minimized. it can. Also, the current consumption for moving the roller can be minimized.

According to a fourth aspect of the present invention, in the document feeder according to the first aspect, there is an operating means for designating a document size, and the control means judges that the document size designated by the operating means is the original size. The configuration is performed based on whether or not the set value is exceeded.

According to this structure, it is determined whether or not the roller on the first reversing path should be separated from the original based on the original size designated by the operating means. As a result, if the original size is smaller than the set value, the roller is not moved, and only if the original size is longer than the set value, the roller is moved. Therefore, move the roller only when it is necessary to actually move it. It is possible to suppress the generation of abnormal noise due to the movement of the roller. Also, the current consumption for moving the roller can be minimized.

A multifunction machine according to a fifth aspect of the present invention is a first conveyance path for conveying a document on a platen to a reading point and a document conveyed from the front end by reversing the rotation direction of a roller. A first reversing path that discharges from the end to change the conveying direction, a second conveying path that conveys from the first conveying path to the first reversing path, and a document whose first surface has been read from the first reversing path. A third conveyance path for returning to the first conveyance path, a second reversal path for reversing and discharging the front and back of a document whose second surface has been read from the first reversal path, and a document for which the second surface has been read. When it is determined that the trailing edge of the same document exists in the first reversing path when it is detected that the leading edge enters the first reversing path, a control unit that separates the roller of the first reversing path from the document. Adopt a configuration that has.

According to this structure, when it is detected that the leading edge of the original whose second surface has been read enters the first reversing path,
If it is determined that the trailing edge of the same document exists in the first inversion path,
The roller of the first inversion path is separated from the original. As a result, even when a double-sided original having a long original length is conveyed, the rollers of the first reversing path do not prevent the leading edge of the original from entering the first reversing path. It is possible to avoid a situation in which the progress is hindered, the original is jammed in the first reverse path, and a paper jam occurs.

According to a sixth aspect of the present invention, in the multi-function peripheral according to the fifth aspect, the control means judges that the document length is measured by a sensor on the conveyance path and whether the measured value exceeds a set value. The configuration based on the crab is adopted.

According to this structure, it is determined whether or not the roller on the first reversing path should be separated from the original based on the actual length of the original conveyed on the conveying path. As a result, the roller is not moved when the document length is shorter than the set value, and the roller is moved only when the document length is longer than the set value. Therefore, the roller should be moved only when it is necessary to actually move it. It is possible to minimize the generation of noise due to the movement of the roller. Also, the current consumption for moving the roller can be minimized.

According to a seventh aspect of the present invention, in the composite machine according to the fifth aspect, the control means makes a determination based on whether or not the size of the document set on the platen exceeds a set value. Take.

According to this structure, it is determined whether or not the roller of the first reverse path should be separated from the original based on the size of the original set on the original table. As a result, if the document size is smaller than the set value, do not move the roller,
Since the roller is moved only when the document size is longer than the set value, the roller can be moved only when it is necessary to actually move it, and the generation of abnormal noise due to the movement of the roller can be minimized. it can. Also, the current consumption for moving the roller can be minimized.

According to an eighth aspect of the present invention, in the multi-function peripheral according to the fifth aspect, there is provided operation means for designating a document size, and the control means judges that the document size designated by the operation means is set. The configuration is performed based on whether or not the value is exceeded.

According to this structure, it is determined whether or not the roller of the first reversing path should be separated from the original based on the original size designated by the operating means. As a result, if the original size is smaller than the set value, the roller is not moved, and only if the original size is longer than the set value, the roller is moved. Therefore, move the roller only when it is necessary to actually move it. It is possible to suppress the generation of abnormal noise due to the movement of the roller. Also, the current consumption for moving the roller can be minimized.

An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic configuration diagram of a multi-function machine 100 including a document feeder according to an embodiment of the present invention.

As shown in FIG. 1, the present multi-function peripheral 100 is provided with a reading unit 101 for reading a document on the upper part thereof.
A main body unit 102 for performing paper feed, transfer, recording, and fixing processes is provided below the main unit.

On the upper surface of the reading unit 101, an operation panel as an operating means is provided. The operation panel is
For example, it is composed of a liquid crystal display unit, and displays the current state of the multifunction peripheral 100.

An opening / closing cover (not shown) is provided on the front surface of the main unit 102 for replacing the toner bottle or removing a paper jam. When this open / close cover is opened, power supply to a drive system, which will be described later, in the multifunction machine 100 is cut off in consideration of safety.

A paper feed tray 103 is installed at the bottom of the main unit 102. The uppermost sheet from the bundle of sheets set in the sheet feed tray 103 is picked up by the pickup roller 10
Taken out by 4.

The paper taken out from the paper feed tray 103 is sent by a paper feed roller 105 to a paper path 106 formed upward from the bottom of the main body unit 102. A plurality of intermediate rollers 107 and 108 are arranged in the paper path 106.

The sheet conveyed by the intermediate roller 108 arranged above is passed to the registration roller 110 by the intermediate roller 109. A photosensitive drum 111 that rotates in the direction of the arrow in the drawing is arranged at the destination of the sheet conveyed by the registration rollers 110.

Above the photoconductor drum 111, an LSU (Laser) for forming a latent image on the surface of the photoconductor drum 111.
Scan Unit) 112 is arranged. Photoconductor drum 1
A developing device 113 for adhering a developer (toner) to the latent image formed on the photosensitive drum 11 is arranged adjacent to the photosensitive drum 111. The developer is agitated inside the developing device 113.
A stirring roller for conveyance and a developing roller 114 for adhering the developer to the photosensitive drum 111 are provided.

Below the photoconductor drum 111, a transfer device 115 for transferring the image formed by the developer adhering to the photoconductor drum 111 to the conveyed paper is installed. The registration roller 110 controls the position adjustment between the image on the photosensitive drum 111 and the recording area of the paper.

Photoreceptor drum 111 after transfer of image
Unit 116 for cleaning the surface of
Are arranged adjacent to the photosensitive drum 111. The sheet on which the image is transferred is further conveyed by the conveyor belt 117. The fixing unit 1 is provided at the conveyance destination of the conveyance belt 117.
18 are arranged.

The fixing unit 118 includes a fixing roller 119.
And the pressure roller 12 arranged to face the fixing roller 119.
0, and a cleaning roller (not shown) for applying oil to enhance the peeling property of the toner remaining on the fixing roller 119. The fixing roller 119 applies heat to the recording surface of the paper, and the pressure roller 120 fixes the paper to the fixing roller 11.
By pressing between 9 and 9, the image is fixed on the paper.

The sheet discharged from the fixing unit 118 is discharged to the outside of the main body unit 102 by the discharge roller 121. The sheet discharged from the main body unit 102 is received on the sheet discharge tray 122.

A switching guide 124 is provided between the fixing unit 118 and the discharge roller 121 to switch between discharging the paper to the outside of the main body unit 102 and sending it to a double-sided path 123 for double-sided recording. The double-sided path 123 is formed downward from the vicinity of the switching guide 124, and is formed substantially horizontally in the middle thereof.

The sheet sent to the double-sided path 123 is temporarily drawn by the reverse roller 125 into the reverse path 126 formed on the extension of the downwardly formed portion 123A of the double-sided path 123. When the sheet is drawn into the reversing path 126, the reversing roller 125 reverses the sheet, and the part 123 of the double-sided path 123 is formed in a substantially horizontal direction.
Send to B. At this point, the front and back of the paper are reversed.

Double-sided path 123B formed in a substantially horizontal direction
The sheet fed into the sheet is conveyed by the conveying rollers 127, 128 and 129 formed on the double-sided path 123B. The double-sided path 123B is connected to the paper path 106 below the transport roller 109. Conveyor rollers 127, 12
The paper that has been conveyed to the paper path 106 by the double-sided path 123B by 8 and 129 is again conveyed to the photoconductor drum 11.
1 is fed below, and an image is formed on its back surface this time.

A manual feed tray 130 is provided on the side surface of the main body unit 102. The topmost sheet of the sheet stack placed on the manual feed tray 130 is the pickup roller 131.
Are taken in by the transfer roller 132 and transferred to the registration roller 110 by the transport roller 132.

Further, an LCT is provided on the side surface of the main unit 102.
(Large Capacity Tray) 133 is provided. L
The CT 133 is used when forming an image on a large amount of paper. The LCT 133 operates by receiving power supply from the multi-function peripheral 100.

A large amount of sheets are placed on the bottom of the LCT 133, and an elevating table 134 for raising the uppermost sheet to a predetermined position is provided. The uppermost sheet of the sheet bundle that has risen to a predetermined position is taken out by the pickup roller 135. The paper taken out from LCT133 is
The paper is fed to the paper path 106 by the paper feed roller 136.

FIG. 2 is a functional block diagram for controlling the multi-functional peripheral 100 according to the present embodiment having such a configuration.

As shown in the figure, the multi-function peripheral 100 is for controlling the entire multi-function peripheral 100 and a central processing unit 200 for accepting operation instructions from the user and presenting various information to the user. An operation panel 300, an image forming unit 400 that forms an image on a sheet, a document reading unit 500 that reads a document, and a power supply 600 that supplies power to each of these units.

In the central processing unit 200, the CPU 2 forming a part of control means via the system bus 201.
A ROM 203 and a RAM 204 are connected to 02. The ROM 203 is used as a storage area for storing a program for the CPU 202 to control the entire multifunction peripheral 100, and the RAM 204 is used as a storage area for securing a work area of the CPU 202.

The system bus 201 has an image reading unit interface (I / F) 205, an image processing unit 206, a codec 207, and an image forming unit interface (I / F).
F) 208 is connected.

Image reading interface (I / F) 20
Reference numeral 5 is a portion for connecting the document reading unit 500 and the system bus 201 to edit the read image data. The image processing unit 206 is an image processing circuit that enlarges / reduces image data or rotates the image data at an arbitrary angle. Codec 2
Reference numeral 07 is a portion for performing encoding / decoding processing on the image data. Image forming unit interface (I / F) 20
Reference numeral 8 is a portion for transmitting the image data of the recorded image from the central processing unit 200 to the image forming unit 400.

These image reading interface (I /
The image memory 210 and the image storage memory 211 are connected to the F) 205, the image processing unit 206, the codec 207, and the image forming unit interface (I / F) 208 via the local bus 209.

The image data read by the document reading unit 500 is stored in the image memory 210.
In 11 is stored image data that has been encoded by the codec 207. These devices are connected by the local bus 209 in order to speed up data transfer between the devices.

Further, a print data acquisition interface (I / F) 212 is connected to the system bus 201. Print data import interface (I / F) 212
Captures print data created by a data terminal device such as a personal computer (PC).

In the image forming section 400, the CPU 40 forming a part of the control means via the system bus 401.
2, a ROM 403 and a RAM 404 are connected.
The ROM 403 is used as a storage area for storing a program for the CPU 402 to control the image forming unit 400 and the document reading unit 500, and the RAM 404 is C
It is used as a storage area for securing a work area or the like of the PU 402.

The image forming section 400 includes a paper feed tray 103 for accommodating paper sheets, and a tray lift portion 405 for elevating and lowering a paper tray on which a bundle of paper sheets is placed.
A paper transport unit 406 that transports the paper taken out from the paper feed tray 103, an image recording unit 407 that records an image on the paper taken out from the paper feed tray 103, and an image recorded on the front surface of the paper is fixed to the paper. Fixing unit 118
And are equipped with. These are controlled by the CPU 402.

The tray lift section 405 raises the sheet tray to a position where the uppermost sheet of the sheet bundle is taken out by the pickup roller 104, and the sheet conveying section 406 switches the roller that gives the power of the drive motor as described later. To convey the paper.

The image recording section 407 includes a photosensitive drum 111.
While rotating the LSU 112,
A latent image is formed on the sheet, and a predetermined voltage is applied to the transfer unit 115 to transfer the image on the photosensitive drum 111 onto the sheet.

The paper feed tray 103, the tray lift portion 405, the paper transport portion 406, the image recording portion 407, and the fixing unit 118 are portions that the user can contact when the above-mentioned opening / closing cover is opened. Therefore, when the opening / closing cover is opened, it is necessary to stop the driving of these. Therefore, in the multi-function peripheral 100, the power supply to these is forcibly shut off when the open / close cover is opened.

In the present embodiment, these paper feed tray 103, tray lift unit 405, and paper transport unit 40 are provided.
6, the image recording unit 407 and the fixing unit 118 are referred to as a drive system 408.

When a paper feed error occurs in the multi-function peripheral 100, the CPU 402 shuts off the power supply to the drive system 408 in advance in consideration of the possibility of opening the open / close cover. In this way, double safety management is performed.

The LCT 133 described above is based on this drive system 408.
Power is supplied at the same timing as the power supply to. Therefore, when the power supply to the drive system 408 is cut off, the power supply to the LCT 133 is also cut off.

The document reading section 500 includes a reading unit 101.
Document scanning unit 501 for scanning the surface of the document set on the
And an automatic document feeder 502 for conveying the document set in the reading unit 101. As shown in FIG. 2, the document reading unit 500 is connected to the CPU 402 via the system bus 401, and the document scanning unit 501 and the automatic document feeding unit 502 are controlled by the CPU 402.

FIG. 3 is a side sectional view showing the structure of the document feeder according to the present embodiment. The document feeder is applied in the reading unit 101 shown in FIG. The left side of FIG. 3 is referred to as the left side of the device.
The right side of is called the right side of the device.

The original document feeder is provided with an original table 301 on which the original document is placed. The document table 301 is connected to the inner cover 302 of the document feeder.
A document is placed across the document table 301 and the inner cover 302.

An outer cover 303 of the document feeder is arranged above and facing the inner cover 302. The inner cover 302 and the outer cover 303 are configured so that they can be opened and closed independently or in conjunction with each other so that the conveyance path of a document can be exposed when a paper jam occurs.

A pickup roller 304 is supported near the lower surface of the outer cover 303. The pick-up roller 304 sends the uppermost original among the originals placed on the original table 301 or the like to the contact surface of the paper feed roller 305 and the separation roller 306 arranged on the left side of the apparatus.

While the originals are further fed to the inside of the apparatus by the paper feed roller 305, the originals are separated one by one by the separation roller 306. A pad 307 is provided on the upper surface of the inner cover 302 for pushing up the document and preventing the last one document from staying.

The document fed by the paper feed roller 305 advances along a conveyance path continuously provided from the paper feed roller 305. This conveyance path constitutes a path in which the document fed to the left side of the apparatus by the sheet feeding roller 305 is once advanced downward, and then the direction is changed to proceed to the right side of the apparatus. The detailed configuration of this transport path will be described later.

The first registration roller 30 is placed on this conveyance path.
8, a second registration roller 309 and a conveyance roller 310 are arranged. A guide 311 is provided between the first registration roller 308 and the second registration roller 309 and on the left side of the apparatus on the conveyance path to absorb the bending of the conveyed document. A reading mirror 312 of a document reading unit for reading a document is arranged below the transport path between the second registration roller 309 and the transport roller 310. The reading mirror 312 constitutes a reading point of the document.

The switching guide 3 is provided at the destination of the transport roller 310.
13 are arranged. The switching guide 313 switches the conveyance direction of the original between reading both sides of the original and reading one side of the original. When reading both sides, the document formed toward the top of the device is advanced to the conveyance path for reversing, while when one side is read, the document formed toward the right side of the device is discharged. To the transport path for.

The switching guide 313 is rotatably supported by the transport guide 314. The transport guide 314 is arranged at the transport destination of the transport roller 310, and constitutes a part of the transport path on its side surface, upper surface, and lower surface.

The transport guide 314 rotatably supports the reversing guide 315 on the right side and the upper side of the apparatus. The reversing guide 315 is for switching the conveying direction of a document pulled back to the left side of the apparatus by a reversing roller described later.

A central cover 316 is provided on the right side of the apparatus at a position facing the transport guide 314 and the reversing guide 315.
Are arranged. The central cover 316 forms the lower surface of the transport path for reversing the original at its upper surface, and forms the upper surface of the transport path for discharging the original at its lower surface.
Like the inner cover 302 and the outer cover 303, the central cover 316 is configured to be retractable to the right side of the apparatus so that the conveyance path of a document can be exposed when a paper jam occurs.

The center cover 316 supports the reversing roller 317 near the upper surface thereof. A driven roller 318, which is driven by the reversing roller 317, is supported by an elevating table 319 that is arranged to face the upper surface of the central cover 316. Lift 3
19 is controlled to rise in a predetermined case to separate the driven roller 318 from the reversing roller 317. The structure and operation of the lift 319 will be described later.

The reversing roller 317 sends the conveyed original document to the sub-tray 320, and at the same time pulls the original document sent to the sub-tray 320 back to the inside of the apparatus from the rear end. The original to be reversed is temporarily placed on the sub-tray 320.

A discharge roller 321 is arranged on the conveyance path formed below the center cover 316. The discharge roller 321 discharges a document whose one or both sides have been read to the discharge table 322.

The structure of the conveying path formed in the document conveying apparatus having the above structure will be described with reference to FIG. FIG. 4 is an enlarged view of a main part of the document feeder according to the present embodiment.

The first conveying path 411 is constituted by the conveying path until the original placed on the original table 301 is conveyed to the reading mirror 312 (reading point). As shown in FIG. 4, the first transport path 411 transports a document to the left side of the apparatus, and then transports the document with the transport direction facing downward.

On the other hand, the first reversing path 412 is constituted by a conveying path for changing the conveying direction of the original by pulling back the original fed from the front end by the reversing roller 317 from the rear end. Specifically, the first inversion path 412 is formed around the inversion roller 317 and above the central cover 316.

The second transport path 413 is configured as a transport path for transporting an original from the first transport path 411 to the first reversing path 412. As shown in FIG. 4, the second transport path 413 transports the document upward as it moves from the position of the reading mirror 412 to the right side of the apparatus.

The third conveyance path 4 is a conveyance path for returning the original, one side of which has been read from the first reversal path 412, to the first conveyance path 411.
14 are configured. The third transport path 414 is the first reverse path 4
It is provided by being extended to the left side of 12 devices. The third conveyance path 414 conveys the document substantially horizontally toward the left side of the apparatus and relays it to the first conveyance path 411.

The second reversing path 4 is a conveyance path for discharging a document whose both sides have been read from the first reversing path 412 to the discharge table 322.
15 are configured. The second inversion path 415 is connected to the first inversion path 4
It is provided so as to extend below 12 devices. Further, the second reversing path 415 is formed in a U-shaped path opened to the right side of the apparatus, and gently guides the conveying direction of the document fed from the first reversing path 412 to the right side of the apparatus.

A plurality of manuscript detecting sensors of the first sensor (SNS1) to the sixth sensor (SNS6) are arranged on the conveying path thus configured. These first sensors (S
According to the detection of the document by the NS1) to the sixth sensor (SNS6), the rotation of various rollers and the elevation of the elevation table 319 are controlled. Hereinafter, these first sensor (SNS1) to sixth
The position of the sensor (SNS6) will be described.

A first sensor (SNS1) is provided at a position for detecting a document placed on the document table 301 and the inner cover 302, and a second sensor is provided at a position for detecting a document sent from the document table 301 or the like into the apparatus. A sensor (SNS2) is provided.

A third sensor (SNS3) is provided at a position for detecting an original document passing through the first transport path 411, and a fourth sensor (SNS4) is provided at a position for detecting an original document passing through the second transport path 413. ing.

A fifth sensor (SNS5) is provided at a position for detecting a document passing through the third conveying path 414, and a sixth sensor (SNS6) is provided at a position for detecting a document passing through the second reversing path 415. ing.

The lifting table 319 described above has the first inversion path 41.
2, the driven roller 318 is moved up and down so as to be separated from the reversing roller 317. Here, the structure of the lift 319 will be described. FIG. 5 is an enlarged view of the vicinity of the lift table 301 of the document feeder according to the present embodiment.

As shown in FIG. 5, the lift table 319 rotatably supports two driven rollers 318 at positions corresponding to the reversing rollers 317 arranged below. Lift 3
19 is swingably supported by a shaft 510 provided at one end on the left side of the apparatus shown in FIGS. 3 and 4.

An electromagnetic solenoid 511 is arranged so as to engage with one end of the lift 319. The electromagnetic solenoid 511 is used to control the elevation of the elevator 319.

The electromagnetic solenoid 511 includes a fourth sensor (S
A shaft core 5 that moves up and down according to the document detection by NS4)
It has twelve. One end of a connecting lever 513 is attached to the peripheral surface of the shaft core 512. On the other hand, the other end of the connecting lever 513 is provided with an engagement piece 514 that engages with the lower surface of the lift 319.

The coupling lever 513 is swingably supported by a shaft 515 fixed to the apparatus casing near the center. When the shaft core 512 moves downward, the engaging piece 514 arranged on the opposite side across the shaft 515 moves upward. In response to this, the lifting table 319 also moves upward with one end on the right side of the apparatus shown in FIGS. 3 and 4 with the shaft 510 as a fulcrum. At this time, the driven roller 318 is separated from the reversing roller 317.

Next, the document conveying operation of the document conveying device having the above structure will be described. FIG. 6 is a flow chart for explaining the overall flow of the document transport operation of the document transport device according to the present embodiment.

It is assumed here that a double-sided original is conveyed. Since the double-sided original is conveyed, the switching guide 313
Switches the transport direction so that the document is transported to the second transport path 413. Further, of the double-sided original, the surface to be read first is referred to as a first surface, and the surface to be read later is referred to as a second surface.

When starting the document feeding operation, the document feeding apparatus first performs a document feeding process (ST601).
In this document feeding process, the document placed on the document table 301 moves on the first transport path 411 to the second registration roller 30.
It is transported to 9. FIGS. 7A to 7E are schematic diagrams showing the state of the original document in the original document feeding device corresponding to the original document feeding process. It should be noted that in the schematic diagrams shown below, documents are indicated by thick solid lines.

Next, the document feeder carries out the first side reading process (ST602). In the first side reading process, the document whose first side is read is conveyed through the second conveying path 413,
It is switched back in the first reversing path 412 and again conveyed to the second registration roller 309 via the third conveying path 414. 8 (a)-(g) and 9 (a)-
(E) is a schematic diagram showing a state of an original document in the original document conveying apparatus corresponding to the first side reading process.

Next, the document feeder carries out the second side reading process (ST603). In the second side reading process, the document whose second side has been read is conveyed to the position where it is conveyed on the second conveying path 413 and is then sent to the second reversing path 415 on the first reversing path 412. FIGS. 10A to 10E and FIGS. 11A and 11B are schematic diagrams showing the state of the original document in the original document feeder corresponding to the second side reading process.

Finally, the document feeder carries out document discharge processing (ST604). In the document discharge processing, the document is conveyed through the second inversion path 415 and is discharged onto the discharge table 322. FIGS. 12A to 12C are schematic views showing the state of the original document in the original document conveying device corresponding to the original document discharge process.

The document feeding process, the first side reading process, the second side reading process, and the document discharging process will be described below using the flow of each process with reference to the corresponding schematic diagrams. Hereinafter, the document feeding process, the first side reading process, the second side reading process and the document discharging process will be described in this order.

FIG. 13 is a flow chart for explaining the document feeding process in this document feeder. 14 and 15 are flow charts for explaining the first side reading process in the present document feeder. FIG. 16 and FIG. 17 are flow charts for explaining the second side reading process in this document feeder. FIG. 18 is a flow chart for explaining the document discharge process in the document feeder.

When the document feeding process is started, the document feeding apparatus firstly picks up the pickup roller 304 and the feeding roller 3.
05 and the first registration roller 308 are rotated (ST
1301). As a result, the document placed on the document table 301 is fed in the direction of the first transport path 411. Note that FIG.
In (a), the document is firstly picked up by the pickup roller 304.
It shows a state in which the sheet has begun to be fed in the direction of the transport path 411.

When the conveyance of the original is started, the second sensor (S
It is monitored whether NS2) is turned on, that is, whether the second sensor (SNS2) has detected the leading edge of the document (S2).
T1302). FIG. 7B shows a state when the leading edge of the document enters the detection area of the second sensor (SNS2),
FIG. 7C shows a state in which the leading edge of the document has passed the detection area of the second sensor (SNS2) and reached the first registration roller 308.

When the second sensor (SNS2) is turned on, it is monitored whether the third sensor (SNS3) is turned on, that is, whether the third sensor (SNS3) detects the leading edge of the document. (ST1303). FIG.7 (d) is
The state at the time when the leading edge of the document enters the detection area of the third sensor (SNS3) is shown.

When the third sensor (SNS3) is turned on, the original document feeding apparatus determines that the third sensor (SNS3)
Starts counting the set time of a timer (hereinafter, referred to as "roller arrival timer") that monitors the time when the leading edge of the document that has passed through the detection area reaches the second registration roller 309 (ST1304), and sets the roller arrival timer. It waits for the passage of time (ST1305).

If the time set by the roller arrival timer has elapsed, it is determined that the leading edge of the original has reached the second registration roller 309, and the pickup roller 304 and the paper feed roller 3
05 and the first registration roller 308 are stopped (S
(T1306), and proceeds to the first surface reading process. By stopping the document once, the document positioning accuracy is improved. FIG. 7E shows a state in which the leading edge of the original has reached the second registration roller 309.

Upon shifting to the first side reading process, as shown in FIG. 14, the original conveying apparatus first rotates the second registration roller 309 and the conveying roller 310 (ST14).
01). Then, a timer (hereinafter, referred to as a "reading start position detection timer") that monitors the time when the leading edge of the document that has passed through the second registration roller 309 reaches the reading mirror 312.
Start counting the set time of (ST1402),
The system waits until the set time of the reading start position detection timer elapses (ST1403).

When the set time of the reading start position detection timer has elapsed, it is determined that the leading edge of the document has reached the reading mirror 312, and the document reading unit starts reading the document (ST1404). As a result, reading of the first side of the document is started. FIG. 8A shows a state in which the leading edge of the original has reached the reading mirror 312.

After starting the reading of the first side of the original, whether the fourth sensor (SNS4) is turned on in the original conveying apparatus, that is, whether the fourth sensor (SNS4) detects the leading edge of the original. Is monitored (ST1405). Figure 8
(B) shows the state at the time when the document enters the detection area of the fourth sensor (SNS4).

When the fourth sensor (SNS4) is turned on, this document feeder rotates the reversing roller 317 in the direction of feeding the document to the sub tray 320 (S).
T1406).

The direction in which this original is sent to the sub-tray 320 matches the direction in which the original is read by the original reading unit. Therefore, in the following, this direction will be referred to as the reading direction, and the opposite direction will be referred to as the reverse direction. I shall. FIG. 8C shows a state in which the original is conveyed in the reading direction by the reversing roller 317.

While the document is conveyed in the reading direction, it is monitored whether the second sensor (SNS2) is in the OFF state, that is, whether the trailing edge of the document has passed the detection area of the second sensor (SNS2) (ST1407). . FIG. 8D shows the state at the time when the trailing edge of the original has passed the detection area of the second sensor (SNS2).

If the second sensor (SNS2) is in the OFF state, the original document feeder determines the length of the original document (hereinafter,
The “original length” is stored (ST1408). The sheet length stored here is used when reading the second side.

Next, whether the third sensor (SNS3) is turned off, that is, the trailing edge of the document is the third sensor (SNS).
It is monitored whether it has passed the detection area of 3) (ST140).
9). In FIG. 8E, the trailing edge of the document is the third sensor (SNS).
The state at the time of passing the detection region of 3) is shown.

When the third sensor (SNS3) is turned off, a timer (hereinafter, referred to as "the timer for monitoring the time when the trailing edge of the original that has passed through the detection area of the third sensor (SNS3) passes through the reading mirror 312". The counting of the set time of the "reading end position detection timer") is started (ST141
0), waiting for the elapse of the set time of the reading end position detection timer (ST1411).

When the set time of the reading end position detection timer has elapsed, it is judged that the trailing edge of the original has passed the reading mirror 312, and the reading of the original by the original reading unit is finished (ST1412). FIG. 8F shows a state in which the trailing edge of the original has passed the reading mirror 312.

Next, whether the fourth sensor (SNS4) is in the OFF state, that is, the trailing edge of the document is the fourth sensor (SN4).
It is monitored whether it has passed the detection region of S4) (ST141).
3). In FIG. 8G, the trailing edge of the document is the fourth sensor (SNS).
The state at the time of passing the detection region of 4) is shown.

When the fourth sensor (SNS4) is turned off, as shown in FIG.
A timer (hereinafter, referred to as a "reverse position detection timer") that monitors the time when the trailing edge of the document that has passed the detection area of the fourth sensor (SNS4) reaches a position at which the document is reversed (hereinafter referred to as "reversed position"). Counting of the set time of () is started (ST1501), and the elapse of the set time of the reverse position detection timer is awaited (ST1502).

When the set time of the reverse position detection timer has elapsed, it is determined that the trailing edge of the original has reached the reverse position, the direction of rotation of the reverse roller 317 is switched to the reverse direction, and the first registration roller 308 is rotated. (ST150
3). As a result, the document is sent to the third transport path 414. At this time, one end, which was the trailing end of the document until now, becomes the leading end of the document. FIG. 9A shows a state in which one end, which has been the trailing end of the original document, has reached the reverse position.

When the document is fed into the third transport path 414, it is monitored whether the fifth sensor (SNS5) is turned on, that is, whether the fifth sensor (SNS5) detects the leading end of the document (ST1504). . 9B shows the state when the leading edge of the document enters the detection area of the fifth sensor (SNS5), and FIG. 9C shows the state where the leading edge of the document passes through the detection area of the fifth sensor (SNS5). Then, the state of reaching the first registration roller 308 is shown.

If the fifth sensor (SNS5) is turned on, is the third sensor (SNS3) turned on?
That is, it is monitored whether the third sensor (SNS3) has detected the leading edge of the document (ST1505). FIG. 9D shows a state when the document enters the detection area of the third sensor (SNS3).

When the third sensor (SNS3) is turned on, this document feeder starts counting the roller arrival timer setting time in the same manner as ST1304 (ST1506), and sets the roller arrival timer. Wait for the passage of time (ST1507).

If the time set by the roller arrival timer has elapsed, it is determined that the leading edge of the original has reached the second registration roller 309, and the rotations of the first registration roller 308 and the reversing roller 317 are stopped (ST1508). The process moves to the two-sided reading process. Here again, the accuracy of positioning the document is improved by stopping the document once. Figure 9
(E) shows a state in which the leading edge of the original has reached the second registration roller 309.

When the process moves to the second side reading process, as shown in FIG. 16, the document transporting apparatus first rotates the second registration roller 309 and the transporting roller 310 and the reversing roller 317 in the reversing direction. (ST160
1).

Then, in the same manner as ST1402 and ST1403, counting of the set time of the reading start position detection timer is started (ST1602), and the elapse of the set time of the reading start position detection timer is awaited (ST1603).

When the set time of the reading start position detection timer has elapsed, it is determined that the leading edge of the document has reached the reading mirror 312, and the document reading unit starts reading the document (ST1604). As a result, reading of the second side of the document is started. FIG. 10A shows a state in which the leading edge of the original has reached the reading mirror 312.

After the reading of the second side of the document is started, whether the fourth sensor (SNS4) is in the ON state, that is,
It is monitored whether the fourth sensor (SNS4) has detected the leading edge of the document (ST1605).

When the fourth sensor (SNS4) is turned on, the document feeder determines whether the document length stored in ST1408 is longer than a preset registered value (ST1606). Here, the setting values registered in advance are
This is a value indicating the length of the original that is fed back into the first reversing path 412 even though the front end of the original is present in the first reversing path 412.

If the document length stored in ST1408 is longer than the preset registered value, the document transporting device raises the elevator 319 (ST1607). Specifically, the electromagnetic solenoid 511 is turned on and the shaft core 512 is
Is moved downward to raise the elevating table 319.
As a result, the driven roller 318 arranged to face the reversing roller 317 is separated from the reversing roller 317.

As a result, even when a double-sided original having a long length is conveyed, the driven roller 318 on the first reversing path 412 does not prevent the leading edge of the original from entering the first reversing path 412. It is possible to avoid a situation in which the document is prevented from advancing in the first inversion path 412 and the original is jammed in the first inversion path 412 to cause a paper jam.

In FIG. 10B, the document is the fourth sensor (SN
FIG. 10C shows the state in which the driven roller 318 is separated from the reversing roller 317 as the lifting table 319 rises in the detection area of S4). In this state, the leading end of the document is placed in the first reversing path 412. The state of being sent is shown.

While the document is continuously conveyed while maintaining this state, it is monitored whether the third sensor (SNS3) is in the OFF state, that is, whether the trailing edge of the document has passed the detection area of the third sensor (SNS3). (ST1608). Figure 10
(D) shows the state at the time when the trailing edge of the document passes through the detection area of the 23rd sensor (SNS3).

The length of the original document stored in ST1408 is
If the preset value is shorter than the preset value, the document feeder switches the rotation direction of the reversing roller 317 to the reading direction (ST1609).

This is because, even if the leading edge of the document is fed to the first reversing path 412, it is clear that the trailing edge of the document does not exist in the first reversing path 412.
The rotation direction of is switched to increase the document conveying force.

When the third sensor (SNS3) is turned off, counting of the set time of the reading end position detection timer is started in the same manner as ST1410 (ST1).
610), and waits for the elapse of the set time of the reading end position detection timer (ST1611).

When the set time of the reading end position detection timer has elapsed, it is judged that the trailing edge of the original has passed the reading mirror 312, the reading of the original by the original reading unit is completed, and the elevating table 319 is lowered. Further, the rotation direction of the reversing roller 317 is switched to the reading direction (ST16
12). In FIG. 10E, the rear end of the original is read by the reading mirror 31.
2 shows a state where the vehicle has passed 2.

Next, as shown in FIG. 17, it is monitored whether the fourth sensor (SNS4) is in the OFF state, that is, whether the trailing edge of the document has passed the detection area of the fourth sensor (SNS4) (ST1701). ). FIG. 11A shows the state at the time when the trailing edge of the document passes through the detection area of the fourth sensor (SNS4).

When the fourth sensor (SNS4) is turned off, the trailing edge of the original which has passed through the detection area of the fourth sensor (SNS4) is at a position where the original is ejected (hereinafter referred to as "ejection position"). The counting of the set time of the timer (hereinafter, referred to as “discharge position detection timer”) for monitoring the time to reach (ST1702) is started, and the elapse of the set time of the discharge position detection timer is awaited (ST1703).

When the set time of the discharge position detection timer has elapsed, it is determined that the trailing edge of the original has reached the discharge position, and the rotations of the second registration roller 309, the conveyance roller 310 and the reversing roller 317 are stopped (ST1704). ), And shifts to document discharge processing. Here again, the accuracy of positioning the document is improved by stopping the document once. Figure 11
(B) shows a state in which the trailing edge of the original has reached the ejection position.

When the original discharge processing is started, as shown in FIG. 18, the original conveying apparatus first rotates the discharge roller 321 and the reverse roller 317 in the reverse direction (ST1801). Thereby, the first inversion path 41
The document stopped at 2 is fed to the second reversing path 415.

After the conveyance to the second inversion path 415 is started,
It is monitored whether the sixth sensor (SNS6) is turned on, that is, whether the sixth sensor (SNS6) detects the leading edge of the document (ST1802). FIG. 12A shows the state when the leading edge of the document enters the detection area of the sixth sensor (SNS6), and FIG. 12B shows the leading edge of the document passing through the detection area of the sixth sensor (SNS6). It shows the state of being done.

If the sixth sensor (SNS6) is turned on, it is monitored whether the sixth sensor (SNS6) is turned off, that is, whether the trailing edge of the original has passed the sixth sensor (SNS6). Yes (ST1803). FIG. 12 (c)
Shows the state where the trailing edge of the document has passed the detection area of the sixth sensor (SNS6).

When the sixth sensor (SNS6) is in the OFF state, a timer (hereinafter, referred to as "the timer for monitoring the time when the trailing edge of the original that has passed through the detection area of the sixth sensor (SNS6) arrives at the discharge tray 322". The counting of the set time of the discharge end detection timer) is started (ST1804), and the waiting of the set time of the discharge end detection timer is awaited (ST18).
05).

When the set time of the discharge completion detection timer has elapsed, it is determined that the document has been discharged onto the discharge table 322, the rotations of the discharge roller 321 and the reversing roller 317 are stopped (ST1806), and the document transfer apparatus A series of transport operations is completed.

As described above, according to the document feeding apparatus of the present embodiment, when it is detected that the leading edge of the document whose second surface has been read enters the first reversing path 412, the trailing edge of the same document is detected. When it is determined that the following is present in the first reversing path 412, the driven roller 318 on the first reversing path 412 is separated from the document. As a result, even when a double-sided original having a long original length is conveyed, the driven roller 31 on the first reversing path 412 is conveyed.
No. 8 does not prevent the leading edge of the document from entering the first inversion path 412, so that the document is prevented from advancing in the first inversion path 412, and the document is jammed in the first inversion path 412, causing a paper jam. It can be avoided.

Further, according to the document feeder of the present embodiment, it is determined whether or not the driven roller 318 on the first reversing path 412 should be separated from the document based on the actual length of the document conveyed on the conveying path. . As a result, the driven roller 318 is not moved when the document length is shorter than the set value, and the driven roller 318 is moved only when the document length is longer than the set value. Therefore, the driven roller 318 is driven only when it is necessary to actually move it. The roller 318 can be moved. Therefore, generation of abnormal noise due to the movement of the driven roller 318 can be minimized, and the current consumption for moving the driven roller 318 can also be minimized.

In this embodiment, the case where it is determined whether or not the driven roller 318 on the first reversing path 412 is to be separated from the original is described based on the actual length of the original conveyed on the conveying path. . However, not limited to this,
When the driven roller 318 is separated from the original, it is determined whether the original size set on the original table 301 exceeds a set value or whether the original size designated by the operation panel 300 exceeds the set value. The configuration may be performed based on the crab. Even with such a change, the same effect as that of the present embodiment can be obtained.

[0150]

As described above, according to the present invention, when a double-sided original having a long length is conveyed, it is prevented that the leading edge and the trailing edge of the same original collide with each other on the conveying path to cause a paper jam. can do.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a multi-function peripheral including a document feeder according to an embodiment of the present invention.

FIG. 2 is a functional block diagram for controlling a multi-function peripheral including the document feeder according to the above embodiment.

FIG. 3 is a side sectional view showing the configuration of the document feeder according to the above embodiment.

FIG. 4 is an enlarged view of a main part of the document feeder according to the above embodiment.

FIG. 5 is an enlarged view of the vicinity of a lift table of the document feeder according to the above embodiment.

FIG. 6 is a flowchart for explaining an overall flow of a document transport operation of the document transport device according to the above embodiment.

FIG. 7 is a schematic diagram showing a state of a document corresponding to a document feeding process in the document feeding device according to the embodiment.

FIG. 8 is a schematic diagram showing a state of a document corresponding to a first side reading process in the document conveying apparatus according to the above embodiment.

FIG. 9 is a schematic diagram showing a state of a document corresponding to a first-face reading process in the document feeding device according to the embodiment.

FIG. 10 is a schematic diagram showing a state of a document corresponding to a second side reading process in the document feeding device according to the embodiment.

FIG. 11 is a schematic diagram showing a state of a document corresponding to a second side reading process in the document feeding device according to the embodiment.

FIG. 12 is a schematic diagram showing a state of a document corresponding to a document discharging process in the document feeding device according to the above embodiment.

FIG. 13 is a flowchart for explaining a document feeding process in the document feeder according to the above embodiment.

FIG. 14 is a flowchart for explaining the first side reading process in the document feeder according to the above embodiment.

FIG. 15 is a flowchart for explaining the first side reading process in the document feeder according to the above embodiment.

FIG. 16 is a flowchart for explaining the second side reading process in the document feeder according to the embodiment.

FIG. 17 is a flowchart for explaining the second side reading process in the document feeder according to the embodiment.

FIG. 18 is a flowchart for explaining a document discharge process in the document feeder according to the above embodiment.

FIG. 19 is a side sectional view showing an example of the configuration of a conventional document feeder.

[Explanation of symbols]

100 MFP 301 Platen 302 Inner cover 303 external cover 305 Paper feed roller 308 First registration roller 309 Second registration roller 310 Conveyor roller 312 reading mirror 317 Reversing roller 318 Driven roller 319 Lifting platform 321 discharge roller 411 first transport path 412 1st inversion path 413 Second transport path 414 Third transport path 415 Second inversion path

Continued front page    F term (reference) 2H028 BA03 BA14 BB04                 2H076 AA04 BA24 BA35 BA36 BA48                       BA57 BA58 BA62 BA81 BB04                       BB05                 3F102 AA04 AB01 BA11 BB02 BB03                       CA03 EA03                 5C062 AA02 AA05 AB20 AB32 AB35                       AB41 AC09 AC58 AC67 AC69                       AC71 AF10 BA00                 5C072 AA01 BA13 BA20 NA01 NA07                       RA01 RA05 UA13 WA02

Claims (8)

[Claims] 1. A first transporting document on a document table to a reading point
A conveyance path, a first reversal path that reverses the rotation direction of the rollers to discharge the document conveyed from the leading edge from the rear end and changes the conveyance direction, and conveys the document from the first conveyance path to the first reversal path. A second conveyance path, a third conveyance path that returns the original whose first surface has been read from the first reverse path to the first conveyance path, and a front and back side of the original that has read the second surface from the first reverse path And a second reversing path for reversing and ejecting the document, and the rear end of the same document is present in the first reversing path when it is detected that the leading edge of the document whose second surface has been read enters the first reversing path. When the determination is made, a document feeding device including a control unit that separates the roller of the first reverse path from the document. 2. The document transport according to claim 1, wherein the control unit measures a document length measured by a sensor on a transport path and determines whether or not the measured value exceeds a set value. apparatus. 3. The document feeder according to claim 1, wherein the control means makes a determination based on whether or not the size of the document set on the document table exceeds a set value. 4. An operation means for designating a document size is provided,
2. The document feeder according to claim 1, wherein the control unit makes the determination based on whether or not the document size designated by the operation unit exceeds a set value. 5. A first document transporting document on a document table to a reading point.
A conveyance path, a first reversal path that reverses the rotation direction of the rollers to discharge the document conveyed from the leading edge from the rear end and changes the conveyance direction, and conveys the document from the first conveyance path to the first reversal path. A second conveyance path, a third conveyance path that returns the original whose first surface has been read from the first reverse path to the first conveyance path, and a front and back side of the original that has read the second surface from the first reverse path And a second reversing path for reversing and ejecting the document, and the rear end of the same document is present in the first reversing path when it is detected that the leading edge of the document whose second surface has been read enters the first reversing path. When the determination is made, a multi-function peripheral including a control unit that separates the roller of the first reverse path from the document. 6. The multifunction machine according to claim 5, wherein the control means makes a determination based on whether or not a document length is measured by a sensor on a conveyance path and whether the measured value exceeds a set value. . 7. The multi-function peripheral according to claim 5, wherein the control means makes a determination based on whether or not the size of the original set on the original table exceeds a set value. 8. An operation means for designating a document size is provided,
6. The multi-function peripheral according to claim 5, wherein the control unit makes a determination based on whether or not the document size designated by the operation unit exceeds a set value.