JP3007858B2 - Double-sided document feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double-sided document feeder configured to present both sides of a document on a scanning surface so that images on both sides of the document can be scanned.

[0002]

2. Description of the Related Art Generally, an image forming apparatus such as a copying machine scans both sides of an original such that the images on both sides of the original are scanned when the images on both sides of the original are copied onto both sides of a transfer sheet. A double-sided document feeder (RADF) configured to be presented on a surface is used. As a conventional double-sided document feeder, those disclosed in, for example, U.S. Pat. No. 4,815,722 and JP-A-59-208538 are known.

FIG. 1 shows a configuration example of a conventional double-sided document feeder.
5 (A) to FIG. 15 (F). The double-sided document feeder shown in FIGS. 15A to 15F feeds a plurality of documents 45 stacked on a paper feed tray 44 to a document table (scanning surface) 46 sequentially from the top. A roller 47 and a discharge roller 48 for switching back the original 45 on the original plate 46 to reverse the front and back of the original 45 and discharging after scanning.
And is constituted by.

In order to scan both sides of a document, FIG.
As shown in FIG.
The document 5 is conveyed onto a document table 46 by a paper feed roller 47, and the downward surface of the document 45 set on the document table 46 is scanned as shown in FIG.

As shown in FIGS. 15C and 15D, the original 45 on the original platen 46 is turned upside down by a discharge roller 48 rotating counterclockwise, and
6 is conveyed from the opposite direction. As a result, FIG.
As shown in FIG. 15, the upward surface of the document 45 set on the document table 46, that is, the surface on the opposite side to the case shown in FIG.

When both sides of the original 45 are finally scanned,
As shown in FIG. 15F, the original 45 on the original platen 46 is
In order to shorten the linear length of the transport path, the paper is turned upside down by a paper discharge roller 48 that rotates clockwise and is discharged to the outside.

In this case, the originals 45 discharged to the outside by the discharge rollers 48 are normally stacked on the discharge tray 49 from the bottom, so that the order of the originals 45 is reversed, and When performing page alignment for the discharged original 45, it is necessary to further reverse the front and back. That is, if the scanning of the back surface of the original 45 is completed in the state of FIG. 15E, the image of the original is not scanned through FIGS. 15C, 15D, and 15E without scanning the image of the original.
Discharge as shown in (F).

Alternatively, in the state shown in FIG.
15 (C) and (D), the image of the first document is scanned in the state of FIG. 15 (E), and thereafter, through FIGS. 15 (C) and (D). The opposite side of the document is presented on a document table 46 as shown in FIG. 15E, and after scanning by this image, a discharging operation is performed as shown in FIG. The paper is discharged in the order.

[0009]

However, in the above-described conventional double-sided document feeder, after the scanning of the downward surface of the document has been completed, the document is conveyed by switchback transport in which the document feeding direction is reversed by the discharge roller. When the pages to be ejected are aligned, two switchback conveyances are required. When the size of the original is large, especially when the length in the conveying direction is long, the time required to convey the original becomes longer. There is a problem.

Further, the document must be stopped once after the switchback of the document is completed, and then sent to a position to be scanned or subjected to a discharging process, so that the transport time becomes longer, and thus the scanning time becomes longer. In particular, in order to perform page alignment, it is necessary to carry out the switchback conveyance state twice as described above, and the time required for scanning both sides of an original and discharging the original is considerably long, and the entire scanning time is reduced. It was really long.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a two-sided document feeder capable of reducing the time required to scan both sides of a document in view of the above-mentioned conventional problems.

In particular, an object of the present invention is to control conveyance so as to shorten the time required to scan both sides of a document. In particular, scanning is performed with the leading edge of the document always at the top without performing switchback conveyance. In this case, scanning is performed by feeding the light to the surface.

[0013]

A two-sided document feeder for achieving the above object of the present invention comprises a tray (21) on which documents are stacked, and a feeding means (22) for feeding the documents one by one from the tray. , 23), fed out of the first side of the document by reversing the front and back surfaces of the document feeding write-run査後the scanning surface (36) sends a second side of the document to the scanning surface, the Second
And a transport unit that discharges after scanning the surface of the original, the transport unit (24, 25, 2)
6, 27, 31, 32, and 33) a first transport unit (2) for feeding the first surface of the sent document to the scanning surface.
4, 27), reversing means (31, 32) for reversing the front and back sides of the original without reversing the front and back sides of the original after scanning the first side, and reversing the conveying state by the reversing means. You
In order to feed the second side of the document, whose front and back sides are inverted, to the scanning surface without the need to feed the first side via a transport unit (24) sharing a part of the first transporting means. A second conveying means (24, 26) for feeding in a direction opposite to the direction;
Above the position of the transport unit which is shared part of the first or second
Select the direction to send to the above scanning plane via the conveyance means
And a discharge means (33) for discharging the document after scanning the second surface.

With this configuration, the leading edge of the sent document is always transported as the leading edge, and the first and second surfaces of the document are presented on the scanning surface. Therefore, there is no need to perform switchback conveyance in which the document is conveyed in the reverse direction, so that the time for scanning both sides of the document can be significantly reduced. In addition, both sides of the original should be
Of the first and second transport means for feeding in from opposite directions.
By passing the part through a shared transport unit,
The entire device can be downsized.

Therefore, in the above-described configuration of the double-sided document feeder, if the first and second surfaces of the document are scanned on the scanning surface while conveying the document at a constant speed, the document can be scanned. Since the sheet is always conveyed until it is sent out from the tray and discharged, the scanning time can be greatly reduced.

In the above-described double-sided document feeder, there is provided a means for detecting the size of the document in the transport direction, and the reversing means reverses the document in accordance with the size of the document detected by the detecting means. If the length of the path can be changed, the interval when scanning the front and back surfaces of the document can be made constant regardless of the document size, so that the scanning time can be reduced.

Further, the reversing means is provided with a tray for loading the original.
If it is placed at the bottom of the
Space between the equipment and the
Can be made compact.

In the above-described double-sided document feeder,
When one-sided originals are stacked on the tray,
The output original is partially shared by the first and second transport means.
Through the transport section, and the second transport means
Feed one side of the document to the scanning surface via
For example, even for single-sided originals,
Use the transport means for double-sided documents as they are and send them to the scanning surface
Can be included.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a double-sided document feeder according to the present invention will be described in detail with reference to the drawings.

FIG. 1 shows the configuration of a two-sided document feeder according to an embodiment of the present invention. FIG. 2 is a block diagram showing the configuration of a control circuit for controlling the conveyance of a document by the double-sided document feeder in FIG.

First, referring to FIG. 1, a double-sided document feeder according to the present invention includes a paper feed tray 21, a paper feed roller 22 forming a feeding unit, a pair of rollers 23a and 23b, a pair of conveying rollers 24a and 24a forming a conveying unit. 24b, branch selection unit 25, transport roller pairs 26a, 26b, transport roller pairs 27a, 27
b, forward / reverse rotation roller 28, business card (postcard) tray 29, forward / reverse rotation roller 30, transport roller pair 31 as intake means
a, 31b, a conveyance path 32 having a substantially semi-cylindrical shape having a curved surface, and a pair of paper discharge rollers 33a, 3 constituting discharge means.
3b and a paper discharge tray 34.

Next, the configuration and operation of each of the above-mentioned components constituting the double-sided document feeder will be described.

On the paper feed tray 21, a plurality of originals are stacked, and a paper feed roller 22 for sending out the stacked originals is arranged. The document on the paper feed tray 21 is taken up by the paper feed roller 22 to the position of a pair of rollers 23a and 23b for preventing the taking of two sheets.

Roller 2 above roller pair 23a, 23b
Reference numeral 3a rotates in the document conveying direction (clockwise in the figure), and the lower roller 23b rotates in the same direction as the upper roller 23a (clockwise, that is, the direction opposite to the document conveying direction). I have. Therefore, a plurality of originals are
When the original is taken in by the lower roller 2
3b, only the uppermost document is fed by one sheet. The paper feed roller 22 and the pair of rollers 24a and 24b constitute a feeding unit.

Downstream of the roller pair 23a, 23b,
A transport roller pair 24a, 24b for sending out the document is arranged. The original sent out from the pair of conveying rollers 24a and 24b is sent to a branch selector 25 based on the type of original scanning.
Is conveyed in one direction selected by. for that reason,
The branch selecting unit 25 switches the transport direction when scanning only one side of the document on the scanning surface 36 or when scanning the second surface (second surface) of both sides of the document. The transport roller pair 24a, 2 that can be selected by the branch selecting unit 25
Downstream in one direction 4b, the document is synchronously transported from the right side (the right-hand direction in the drawing) as the second side of the scanning surface 36 to the left side (the left-hand direction in the drawing) as the first side. Transport roller pairs 26a and 26b are arranged.

Also, the first side (first side) of both sides of the document
When scanning is performed, a pair of transport rollers 27a and 27b that synchronously transport the original from left to right on the scanning surface 36 are provided downstream of the pair of transport rollers 24a and 24b that can be selected by the branch selection unit 25 in the other direction. Are located.

The forward / reverse rotation roller 28 is disposed on the scanning surface 36 so that the original can be conveyed in either the left or right direction as described above.

The downwardly facing surface (the image surface is down) of the originals stacked on the paper feed tray 21 is synchronized with the pair of transport rollers 26a, 2 for synchronization.
6b and the forward / reverse rotation roller 28 can scan on the scanning surface 36. Further, the upward facing surface is a pair of transport rollers 27 for synchronization.
a and 27b are inverted by the forward / reverse rotation roller 28 and can be scanned on the scanning surface 36.

The business card tray 2 is located on the left side of the scanning surface 36 in the figure.
9 and a forward / reverse rotation roller 30 for transporting the business card from the name tray 29 onto the scanning surface 36 are arranged.

Downstream of the forward / reverse rotation roller 28 (rightward in the figure), a branch selection unit 37 for branching the transport direction into two directions when scanning the first of both sides of the document is provided by a transport roller pair 31.
a, 31b.

A discharge tray 35 for business cards and postcards is arranged in one direction (rightward in the figure) downstream of the pair of transport rollers 31a and 31b which can be selected by the branch selection section 37.

A substantially semi-cylindrical guide portion 32 is disposed in the other direction downstream of the pair of transport rollers 31a and 31b which can be selected by the branch selecting portion 37. As shown in FIG.
The document reversing conveyance path 32 having a substantially semicircular simple shape so as to form a part of the protruding curved surface has a size corresponding to the size of the document detected by the sensor S27 (that is, the size / length in the conveyance direction). The length of the transport path 32 can be changed so that the document can be turned upside down at a predetermined timing.

Further, the reverse conveyance path 32 having a changed length.
Is configured to return to the neutral position when the sensor S26 detects the end of the document whose front and back are reversed.

Downstream of the reversing conveyance path 32 (to the left in the figure), a pair of conveyance rollers 24a for controlling the direction of the original described above,
24b are arranged.

When scanning only one side of the original on the scanning surface 36 or scanning the second surface (second surface) of both sides of the original, the original is located downstream of the forward / reverse rotation roller 28 (upper left in the figure). Discharge roller pairs 33a and 33b that reverse the original so as to shorten the length of the transport path in the linear direction and discharge the original to an external discharge tray 34 so that the surface to be scanned is directed upward are arranged. Therefore, the documents discharged to the discharge roller pairs 33a and 33b are discharged onto the discharge tray 34 so as to be sequentially stacked from below.

The above-described transport rollers 26a, 26b, 27
Sensors S26, S27, and S31 for detecting a document are arranged upstream of a, 27b, 31a, and 31b, respectively.

Based on the detection signals of the sensors S26, S27 and S31, the pair of transport rollers 24a and 24
b, 31a, 31b, the drive timing of the transport rollers 26a, 26b, 27a, 27b for synchronization, and the drive direction of the forward / reverse rollers 28, 30 are controlled, respectively.

FIG. 2 is a block diagram showing the drive control of the double-sided document feeder shown in FIG.

As shown in FIG. 2, a guide section 41 as a reversing means includes a document size discriminating section 42 connected to the sensor S27, a driving section 43 connected to the document size discriminating section 42 and the sensor S26, and a driving section 43. It is configured by a connected transport unit 32.

The operation of each part constituting the guide section 41 of FIG. 2 will be described below.

The document size discriminating section 42 receives a signal representing the size of the document output from the sensor S27, and detects the size of the document (size in the transport direction) detected by the sensor S27 based on the input signal. Is determined.

The drive section 43 is configured to receive a signal indicating the result of the discrimination by the document size discriminating section 42, and to move the transport path 32 by a predetermined displacement in accordance with the input discrimination result. Further, when a signal is input from the sensor S26 that has detected the end of the document, the drive unit 43 drives the guide unit 41 of the reverse conveyance path 32 to return to the neutral position based on the input signal.

Next, the operation of the double-sided document feeder of this embodiment when scanning only one side of a document will be described with reference to FIGS.

First, the original D is set on the paper feed tray 21 so that the scanning surface faces downward (the state shown in FIG. 3). In the state of FIG. 3, as shown in FIG. 4, the uppermost document D1 set on the paper feed tray 21 is
The document is conveyed to a pair of conveyance rollers 24a and 24b for controlling the direction of the original document by a pair of rollers 23a and 23b for preventing taking in two sheets. The document D1 sent out by the transport roller pairs 24a and 24b is transported by the branch selector 25 in the direction in which the transport roller pairs 26a and 26b for synchronization are arranged.

The leading end of the original D1 is the sensor S
26, a pair of transport rollers 26a,
As shown in FIG. 5, synchronous scanning is performed from the right to the left of the scanning surface 36 by 26b. Original D1 on this scanning surface 35
Is fed from the forward / reverse roller 28 rotating clockwise, and is output by the branch selectors 38 and 39 to the discharge roller pair 3.
The sheet is conveyed to a discharge path in which 3a and 33b are arranged, and discharged onto a discharge tray 34.

Here, during scanning of the original D1, the next original D
2 is transported to the position of the transport roller pair 26a, 26b for synchronization by the feed roller 22, the roller pair 23a, 23b, the transport roller pair 24a, 24b, and the branch selecting unit 25, and the leading end thereof is detected by the sensor S26. .

Subsequently, as shown in FIG.
Are scanned by the conveying roller pairs 26a and 26b for synchronization.
6 is conveyed synchronously from right to left, and sent out from the forward / reverse rotation roller 28 as shown in FIG.
And 39, the paper is conveyed in the direction in which the paper discharge roller pairs 33a and 33b are arranged.

In this case, similarly, the next original D3 is fed to the paper feed roller 22, and the pair of rollers 23a, 23
b, transport roller pair 24a, 24b, and branch selector 2
5, the sheet is conveyed to the position of the conveying roller pair 26a, 26b for synchronization, and the leading end thereof is detected by the sensor S26. Similarly, as shown in FIG. 8, the original D3 is synchronously conveyed from the right to the left of the scanning surface 36 by the conveying roller pairs 26a and 26b for synchronization.

Accordingly, the first tray of the plurality of originals is at the bottom and the last page is at the top of the paper feed tray 2.
The original set on 1 is discharged onto the paper output tray 34 with the last page at the bottom and the scanning surface facing upward, so that the order of the originals on the paper feed tray 21 and the paper output tray 34 is changed. No need.

In other words, when scanning an image on one side of the original, the original bundle having the aligned pages is placed on the paper feed tray 21 with the original scanning side down, so that the final The pages of the document are sequentially sent to the scanning surface 36, and the surface scanned on the paper discharge tray 34 is discharged upward, so that the paper is discharged in the first aligned page order. In this case, in the document bundle, the document of the first page is sent out last and is discharged onto the discharge tray 34.

Next, the control and operation when scanning both sides of a document having images formed on both sides in the present invention will be described with reference to FIGS.

As shown in FIG. 9, the original E set on the paper feed tray 21 has the first surface to be scanned facing upward and the final original at the bottom. Then, the uppermost document E1 is transported to the transport roller pairs 24a and 24b for controlling the direction of the document by the paper feed roller 22 and the pair of rollers 23a and 23b for preventing the taking of two sheets. And the manuscript E1 is
The branch selecting unit 25 conveys the sheet from the pair of conveying rollers 24a and 24b in the direction in which the pair of conveying rollers 27a and 27b for synchronization are arranged, and the leading end thereof is detected by the sensor S27.

Next, as shown in FIG. 10, the document E1 is inverted by the pair of transport rollers 27a and 27b and the forward / reverse rotation roller 28 rotating in the counterclockwise direction, and is synchronously transported from left to right on the scanning surface 36. Then, the first surface of the document E1 set on the paper feed tray 21 is scanned.

The document E1 on the scanning surface 36 is sent out from the forward / reverse rotation roller 28, and sent out by the branch selection unit 40 to the pair of transport rollers 31a and 31b. Then, the document E1 sent out from the pair of transport rollers 31a and 31b is transported by the branch selection unit 37 in the direction of the reverse transport path 32, and
The front and back surfaces are reversed by the reversing conveyance path 32 and are conveyed to the conveyance roller pairs 24a and 24b as shown in FIG.

Further, the original E1 sent out by the transport roller pairs 24a and 24b is transported by the branch selecting unit 25 in the direction in which the roller pairs 26a and 26b are arranged, and the leading end thereof is detected by the sensor S26. Is detected.

The guide section 41 includes a pair of transport rollers 26a, 2
6b and a pair of conveying rollers 31a and 31
When both the sensors S31 upstream of b detect the document E1, as shown in FIG. 11, the document is moved obliquely upward in the drawing at half the speed of the document to increase the transport path length.
When the sensor S31 detects the trailing end of the document E1, the reverse transport path 32 moves diagonally downward in the figure at half the document transport speed as shown in FIG. Return the length to the original length.

In FIG. 12, an original E1 is synchronously conveyed from right to left on a scanning surface 36 by a pair of synchronizing conveying rollers 26a and 26b and a forward / reverse rotation roller 28 rotating clockwise, and fed. The downward surface (second surface) of the document E1 set on the tray 21 is scanned.

Subsequently, as shown in FIG. 13, the original E1 on the scanning surface 36 is conveyed from the forward / reverse rotation roller 28 by the branch selectors 38 and 39 toward the paper discharge rollers 33a and 33b.

The next original E2 is fed by the paper feed roller 22, the roller pair 23a, 23b, the transport roller pair 24a, 24b,
Then, the conveying roller pair 27 for synchronization is set by the branch selecting unit 25.
a and 27b are conveyed upstream of the sensor S27.
Is detected by

When scanning of the first original E1 is completed, FIG.
As shown in FIG. 4, the next original E2 is inverted by the pair of transport rollers 27a and 27b for synchronization and the forward / reverse rotation roller 28 rotating in the counterclockwise direction, and is transported synchronously from left to right on the scanning surface 36. Then, similarly, both sides of the original E2 are similarly scanned.

Therefore, the plurality of originals E set on the paper feed tray 21 such that the first one of the plurality of originals is at the bottom and the last original E1 is at the top are first The back surface (the first surface in this case) and the front surface (the second surface in this case) of the last document E1 are scanned in this order, and the front surface is discharged onto the discharge tray 34 with the front surface facing upward. Hereinafter, the plurality of documents E are sequentially scanned from the last document E1, and the first document is scanned last.
There is no need to change the order of the upper manuscript.

In the above-described document conveyance control, when scanning both sides of the document, the scanning directions are different on the front and back sides, but the first side of the document is read and stored, and the second side is transferred to recording paper. In this case, the directions may be matched.

Further, the direction of the transfer paper may be reversed before transferring the second surface to the recording paper.

Hereinafter, scanning of a double-sided business card will be described as an example of a business card or postcard.

A double-sided business card in which one side is Japanese and the other side is English, the conveying roller 30 with the Japanese side down, that is, the scanning surface 36 side.
Is sent out from the business card tray 29 onto the scanning surface 36.

After the Japanese surface is scanned on the scanning surface 36, the roller pair 31 is switched by the roller 28 through the branch selecting section 40.
a and 31b. The business card conveyed to the roller pair 31a, 31b is further processed by the branch selection unit 37 into the conveyance path 3.
2 and are reversed, after which the roller pairs 24a and 24b
Transported to

Subsequently, the business card is sent out from the pair of rollers 24 a and 24 b by the branch selecting unit 25 in the direction in which the pair of rollers 26 a and 26 b is arranged, and the English surface is scanned on the scanning surface 36.

After the English language surface is scanned on the scanning surface 36, the business card is sent again to the roller pairs 31a and 31b, and is sent from the roller pairs 31a and 31b to the discharge tray 3 by the branch selection unit 37.
The paper 5 is sent out in the direction in which it is arranged, and is discharged onto the discharge tray 35.

As described above, when scanning both sides of an original, when the original is sent out from the paper feed tray 21, the leading end thereof always becomes the leading end, and the first surface of the original and the opposite surface thereof are placed on the scanning surface 36. Will be presented and scanned. Therefore, there is no need to temporarily stop the conveyance as compared with the case where the document is switched back and the conveyance direction is reversed, that is, the front end of the document is the rear end and the rear end is the front end and the conveyance is performed. Therefore, the transport time can be reduced, and the scanning time of the document can be reduced. Scanning surface 3 especially on both sides
In the case of the presentation in No. 6, the switchback transport has to be performed twice, but in the present invention, the switchback transport is not performed, so that the scanning time can be greatly reduced.

Also, after scanning the first surface of the document, a reversing portion for reversing the front and back surfaces of the document when scanning the second surface, that is, the guide portion 42 of the reversing conveyance path 32 in FIG.
Is changed according to the document size detected by the sensor 27 and the document size discriminating section shown in FIG. 2, so that when the rear end of the document passes through the scanning surface, the front and back are reversed regardless of the length of the document. The leading edge of the document can be sent to the scanning surface.
Therefore, the scanning interval of the document can be kept constant irrespective of the document size, and the scanning time can be further reduced.

Further, after scanning the first side of the original, the front and back sides of the original are reversed when scanning the second side.
To the pair of conveying rollers 24a and 24b for scanning the surface of the document, and the second surface is sent to the scanning surface 36 by switching the sending of the original through the rollers by the branch selecting unit 25. I have. Therefore, a part of the transfer path and the transfer means can be used, and the size of the entire apparatus can be reduced.

As described above, the transport roller pair 24
a and 24b and a pair of transport rollers 27a and 27b for synchronization constitute a first transport means, and a reverse transport path 32 including a guide portion 41 reverses the front and back of the document without reversing the transport direction. The reverse means includes a second transport means for feeding the original, whose front and back surfaces have been inverted by the transport roller pairs 24a and 24b and the synchronous transport roller pairs 26a and 26b, to the scanning surface 36 with the scanning direction reversed. And the discharge roller pair 33
The discharge means are constituted by a and 33b, respectively.

The pair of transport rollers 24a and 24b constituting the first transport unit are shared as a part of the transport unit of the second transport unit.
The branching unit for feeding the original conveyed by a and b to the scanning surface 36 is constituted by the branch selecting unit 25.

Further, as shown in FIG. 1, since a reversing conveyance path, which is a reversing means, is provided below the sheet feeding tray 21, the space between the reversing means and the scanning surface 36 can be effectively used, and unnecessary space can be eliminated. The entire device can be made compact.

[0075]

According to the double-sided document feeder of the present invention, the time required to scan both sides of the document can be greatly reduced. In other words, since the top of the document is always conveyed in the feed direction,
Since it is not necessary to perform the switchback conveyance, the time for conveying the document to the scanning surface can be reduced, and thus the scanning time can be shortened.

Further, in order to adjust the path of the reversing conveyance path for reversing the front and back of the document according to the size of the document, the document can be fed to the scanning surface after reversing the front and back regardless of the size of the document.
The scanning interval can be fixed and the time can be shortened.

[0077] Also, by sharing a portion of each conveying means for performing scanning of the first and second surfaces of the document, Ri Do can be miniaturized device, a tray on which a document is loaded By providing the reversing means at the lower part of the device, the size can be further reduced. Furthermore, when sending a single-sided document to the scanning surface,
Also uses some transport means to transport double-sided originals
Is not complicated.

[Brief description of the drawings]

FIG. 1 is a configuration diagram for describing a configuration according to an embodiment of a duplex document feeder according to the present invention.

FIG. 2 is a block diagram illustrating an example of performing drive control of a reverse conveyance path of the duplex document feeder of FIG. 1;

FIG. 3 is a diagram for explaining an operation when one side of the original is scanned by the two-sided original feeder in FIG. 1, and is a diagram showing a state where the original is set.

FIG. 4 is a diagram for explaining an operation in the case where one side of the original is scanned by the double-sided original feeder in FIG. 1, and is a diagram illustrating a state where a first original is fed.

FIG. 5 is a diagram for explaining an operation when scanning one side of a document by the double-sided document feeder in FIG. 1, and is a diagram illustrating a state of scanning a first document and a state of feeding a next document.

6 is a diagram for explaining an operation when scanning one side of a document by the double-sided document feeder in FIG. 1, and is a diagram showing a scanning state of a next document after scanning of a first document is completed. .

FIG. 7 is a diagram for explaining an operation in the case of scanning one side of a document by the two-sided document feeder of FIG. 1; the scanning of the first document is completed and the discharge process is performed; FIG. 11 is a diagram illustrating feeding of a third document.

8 is a diagram for explaining an operation when scanning one side of a document by the double-sided document feeder in FIG. 1, where a first discharge is completed, a next second document is scanned, and a discharge process state is performed. FIG. 9 is a diagram showing a scanning state of a third original.

FIG. 9 is a diagram illustrating an operation when scanning both sides of an original according to the present invention, and is a diagram illustrating a state in which the first uppermost original set on a paper feed tray is fed;

FIG. 10 is a diagram illustrating an operation when scanning both sides of a document according to the present invention, and is a diagram illustrating a scanning state of the first surface of the first document.

FIG. 11 is an explanatory diagram of an operation when scanning both sides of a document according to the present invention, and shows a state in which the scanning of the first surface of the first document is completed and the front and back are reversed for performing the second scanning; FIG.

FIG. 12 is a diagram illustrating an operation when scanning both sides of a document according to the present invention, and is a diagram showing a second scanning state in which scanning of the first surface of the first document is completed and the front and back are reversed. is there.

FIG. 13 is an explanatory diagram of the operation when scanning both sides of a document according to the present invention. When the scanning of both sides of the first document is completed, the first side of the next document is displayed together with the discharge state of the document. FIG. 3 is a diagram illustrating a transport state for scanning.

FIG. 14 is an explanatory diagram of an operation when scanning both sides of a document according to the present invention, showing a state in which the first document is discharged and a state in which the first surface of the next document is scanned.

15A and 15B show a conventional surface document feeder, and FIG.
FIGS. 4A to 4F are operation explanatory diagrams showing a document conveying state and a scanning state. FIGS.

[Explanation of symbols]

Reference Signs List 21 paper feed tray 22 paper feed rollers (feeding means) 23a, 23b roller pair (feeding means) 24a, 24b transport roller pair (first / second transport means) 25 branch selector (Branching means) 26a, 26b Transport roller pair (first transport means) 27a, 27b Transport roller pair (second transport means) 27 Document detection sensor (document size detection means) 28 Forward / reverse rotation rollers 31a, 31b Conveying roller after first surface scanning 32 Reverse conveying path (reversing means) 33a, 33b Discharge roller (discharging means) 34 Discharge tray 36 Scanning surface 41 Guide section (reversing means) 42 Document size discriminating section (document size detecting means) 43) Driving unit for reverse transport path

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G03G 15/00 107 B65H 83/00-85/00

Claims (5)

(57) [Claims] 1. A tray (21) on which documents are stacked, and feeding means (22, 2) for feeding the documents one by one from the tray.
3) scanning the first side of the fed document with a scanning surface (36)
By inverting the front and back surfaces of a document to feed Write-run査後sends a second side of the document to the scanning plane, two-sided document having a conveying means formed by discharge after scanning the surface of the second, the In the feeding device, the transport means (24, 25, 26, 27, 31, 32,
33) a first transporting means (24, 27) for feeding the first side of the sent original to the scanning surface, and without reversing the transporting state of the front and back sides of the original after scanning the first side. inverting means for inverting the front and back surfaces of the document and (31, 32), the reflected
The front and back sides are inverted without reversing the transport state by the rotation means.
In order to feed the second side of the scanned document to the scanning plane, the second side is fed from a direction opposite to the feeding direction of the first side via a conveying section (24) sharing a part of the first conveying means. And a branching means for selectively branching the direction of feeding from the position of the part sharing the transfer part to the scanning surface via the first or second transfer means. 2
5) and a discharge means (33) for discharging the document after scanning the second surface. 2. The double-sided document feeder according to claim 1, wherein the scanning surface scans the first and second surfaces of the document while conveying the document at a constant speed. 3. The apparatus according to claim 1, further comprising means for detecting a size of the document in the transport direction, wherein the reversing means is capable of changing the length of the document reversing path in accordance with the size of the document detected by the detecting means. The double-sided document feeder according to claim 1, wherein: 4. A double-sided document feeder according to claim 1, wherein said reversing means is arranged below a tray on which the documents are stacked. 5. When a single-sided document is stacked on the tray, the sent document is passed through a partially shared transport section of the first and second transport means, and is then transported by the branch means to a second transport section. 2. The double-sided document feeder according to claim 1, wherein one side of the document is fed to the scanning surface via the means.