JPH07261473A - Automatic document feeder - Google Patents

Abstract

PURPOSE:To provide an automatic document feeder capable of easily obtaining a '2 in 1' image without disordering the page even in a both side document by an image forming device. CONSTITUTION:A control means controls a carrying means 3 and an inverse return means 4 so that the preceding document is inverted, returned to a contact glass 18 and positioned in an exposure reference position 19a again when the document is carried and positioned to/on the exposure reference position 19a by the carrying means 3 and then, the exposure of the document is completed, simultaneously controls a paper feeding means 2 so that the succeeding document is fed onto the glass 18, then abutted on the preceding document or approached thereto, and controls the carrying means 3 and the paper feeding means 2 so that the succeeding document is carried and positioned to/on the exposure reference position 19a to arrange two documents on the contact glass 18 side by side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic document feeder, and more particularly to an automatic document feeder suitable for an image forming apparatus such as a copying machine or a facsimile machine.

[0002]

2. Description of the Related Art In recent years, when an image forming apparatus such as a copying machine is used, the cost is reduced and the paper resources are saved by making a copy from a large number of originals with as few sheets as possible. It's starting to happen. Therefore, as a function of the copying machine, a saving mode such as double-sided copying in which an image is formed on both sides of a transfer sheet or so-called “2-in-1” copying in which two originals are arranged and copied onto one transfer sheet has come to be performed. (See, for example, JP-A-2-225241).

Particularly, in the above-mentioned "2-in-1" copy, two originals are arranged side by side and reduced and copied, so that an image of two originals can be formed on one side of a transfer paper of the same size as the original, and a double-sided copy function is provided. By the combination with the above, it is possible to similarly form an image on the back surface of the transfer paper, which is advantageous in that the images of four originals can be collected on one transfer paper.

[0004]

However, in such a conventional "2-in-1" copy-type image forming apparatus, the "2-in-1" -copy originals are limited to single-sided originals, and double-sided originals are not. There is a problem that "2 in 1" cannot be copied. Therefore, the invention according to claim 1 provides an automatic document feeder which allows the image forming apparatus to easily obtain a "2-in-1" image without disturbing the page order of the two-sided document. With the goal.

If the page order of the document discharged after the image formation is not the same as the page order when the document is placed on the document table, it is very inconvenient in handling the document, and If the mechanism for discharging the document and the mechanism for inverting the document surface are separately manufactured, not only the device becomes complicated but also the cost becomes high. In view of this, the invention according to claim 2 is provided with a mechanism in which the page order of the discharged originals matches that when placed on the original placing table, and the reversing mechanism and the discharging mechanism are commonly used. It is an object of the present invention to provide a low-cost automatic document feeder, which simplifies and enhances the reliability of the apparatus.

By the way, in forming a "2 in 1" image, since two originals are arranged side by side, when the size of the preceding original and the size of the succeeding original are not uniform, the formed image lacks image information. Can happen.
In view of this, the invention according to claim 3 is directed to "2i
It is an object of the present invention to provide an automatic document feeder which does not fail in image formation due to a document size mismatch between a preceding document and a succeeding document in forming an “n1” image.

[0007]

In order to achieve the above-mentioned object, the invention according to claim 1 is a document placing table on which a document bundle consisting of a plurality of documents can be placed, and the document stack on the document placing table is the lowest. A sheet feeding means for separating and feeding the originals positioned one by one, and the originals fed from the sheet feeding means are conveyed and positioned at the exposure reference position on the contact glass, and then the originals after the original exposure are set. A transport means that is driven in one direction so as to be carried out from the contact glass, and is also capable of being driven in the other direction so as to transport and position the returned original document to the exposure reference position on the contact glass again, and a contact means by the transport means. Reverse document returning means for reversing the document surface of the document carried out from the glass and returning it to the contact glass again, and two documents arranged side by side on the contact glass with reference to the exposure reference position. The paper feed means so as to place,
Control means for controlling the conveying means and the reverse returning means, wherein the control means conveys the preceding original document to the exposure reference position by the conveying means, and when the exposure of the original document is completed, the conveying means And controlling the reversing and returning means to reverse the original and return it to the contact glass to position it again at the exposure reference position, and to control the paper feeding means to feed the subsequent original onto the contact glass to precede it. The two originals are placed side by side on the contact glass so that they come into contact with or come close to the originals, and then the conveying means and the paper feeding means are controlled so that the succeeding originals are conveyed and positioned at the exposure reference position. It is a feature.

According to a second aspect of the present invention, in the first aspect of the present invention, there is provided reversal ejection means for reversing the document surface of the document conveyed from the contact glass by the conveying means and ejecting it to the outside of the apparatus. The means controls the conveying means to convey the preceding original document which has been exposed to the reverse discharging means, and controls the reverse discharging means to reverse and discharge the original document. The preceding original document is reversed and discharged. Then, the succeeding original document is made to stand by on the contact glass for a predetermined time, and then the conveying means and the reversing and returning means are controlled so that the succeeding original material is reversed and returned to the contact glass and positioned at the exposure reference position again. It is characterized by that.

According to a third aspect of the present invention, in the first aspect of the present invention, a document size detecting means for detecting the size of the document fed on the contact glass and outputting it as a document size detection value, and the document size detection. A document size storage unit that stores the document size detection value output by the unit, a determination unit that compares the size of the preceding document with the size of the following document, and determines the difference between the two sizes, and the main body device. Warning means for transmitting a warning signal to the original size of the preceding original stored in the original size storage means and the original size of the subsequent original detected by the original size detecting means. In comparison, if it is determined that the difference in document size exceeds the predetermined permissible amount, the warning means sends a warning message to the main body device before the start of exposure based on the judgment result of the judgment means. It is characterized in transmitting the.

[0010]

According to the first aspect of the invention, the preceding document is conveyed to the exposure reference position by the conveying means and positioned,
When the exposure of the original is completed, the original is inverted by the conveying unit and the reverse returning unit and returned to the contact glass, positioned at the exposure reference position again, and the subsequent original is placed on the contact glass by the paper feeding unit. When it is fed, it comes into contact with or comes close to the preceding document,
Then, the succeeding originals are conveyed to the exposure reference position by the conveying means and the paper feeding means, and the two originals are juxtaposed on the contact glass so as to be positioned. Therefore, the back side of the preceding document and the front side of the following document can be arranged in a spread, and can be continuously performed.

According to the second aspect of the present invention, the preceding original document, which has been exposed, is conveyed to the reverse discharging unit by the conveying unit, is reversed and discharged by the reverse discharging unit, and the preceding original document is reversed. When the sheet is ejected and discharged, the succeeding original is waited on the contact glass for a predetermined time, and then the succeeding original is reversed by the conveying means and the reversing and returning means and returned on the contact glass to be positioned at the exposure reference position again. To be done. Therefore, at the time of discharging the original, the originals can be stacked in the same page order as the page placed on the original table, and the former reverse ejection processing and the latter reverse of the preceding original and the succeeding original arranged side by side. It is possible to quickly and stably carry out two treatments called treatments.

According to the third aspect of the present invention, the preceding document size stored in the document size storage means and the subsequent document size detected by the document size detection means are compared by the determination means to determine the original size. When it is determined that the difference exceeds the predetermined allowable amount, the warning means sends a warning signal to the main body device before the start of exposure based on the judgment result of the judgment means. Therefore, even if there are irregular sizes in the document, the irregularities can be known before image formation.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. 1 to 12 are views showing an embodiment of an automatic document feeder according to the present invention. First, the configuration will be described.

In FIG. 1, an automatic document feeder 1 includes a paper feed unit 2 (paper feed means), a transport unit 3 (transport means), a reverse discharge unit 4 (reverse return means, reverse discharge means), and a document not shown. Mounting table and control unit (control means, judgment means, warning means)
It is equipped with. The document placing table is capable of placing a document bundle including a plurality of documents.

The paper feed unit 2 includes a pullout drive roller 10,
Pull-out driven roller 11 and rotary encoder 11a
(Control means, document size detection means), paper feed path 12, registration sensor 13 (control means), size detection sensor 14
(Document size detecting means) and a document separating unit (not shown). The pull-out driving roller 10 is rotated clockwise in FIG. 1 by a servo motor (not shown), and cooperates with the pull-out driven roller 11 that is in contact with the pull-out driving roller 10 to feed the document to the paper feed path 13. A rotary encoder 11a is coaxially attached to the rotary shaft of the pullout driven roller 11, and generates a pulse proportional to the rotation amount of the pullout driven roller 11 as the pullout driven roller 11 rotates. This pulse is output as a rotation amount of the pull-out driven roller 11 to a control unit described later. This pull-out driven roller 11
The amount of rotation corresponds to the amount of movement of the original in the paper feeding direction, and the amount of rotation for each time corresponds to the length of the original in the paper feeding direction. The paper feed path 12 is a path for guiding the document conveyed by the pullout drive roller 10 and the pullout pullout driven roller 11 to the conveyance unit 3. Registration sensor 1
Reference numeral 3 is for detecting the leading end of the document fed into the conveyance section 3. The size detection sensor 14 is the paper feed path 1.
2 is provided in the direction orthogonal to the document feeding direction in the middle of 2, and the size of the document passing through the paper feed path 12 in the direction orthogonal to the paper feeding direction is detected, and the detected value is controlled. It is designed to output to the department. The document separating section is composed of a known separation belt, a separation roller, etc., and separates and feeds the lowest document from the document stack on the document mounting table one by one.

The conveying section 3 has a conveying belt 15, a driving roller 16, driven rollers 17a, 17b, 17c and 17d, a contact glass 18, and a reference scale 19.
The conveyor belt 15 is formed of an endless member, and includes a driving roller 16 and driven rollers 17a, 17b, 17c, 17
It is adapted to engage with d. This conveyor belt 15
When the rotating force is applied by the drive roller 16, the document is conveyed on the contact glass 18 in both the reversing and discharging section 4 direction and the paper feeding section 2 direction.
The drive roller 16 is given a rotational force by a servo motor (not shown), and the servo motor is controlled in rotation by a control unit. When the drive roller 16 rotates in the clockwise direction in FIG.
The upper original is conveyed toward the reversing unit 4, and when the drive roller 16 rotates counterclockwise in FIG.
Be transported to. In the following description, when the drive roller 16 rotates clockwise in FIG. 1 and the conveyor belt 15 rotates clockwise, the drive roller 16 rotates normally, and the drive roller 16 rotates counterclockwise in FIG. When the belt 15 rotates counterclockwise is called reverse rotation. The contact glass 18 has a sufficient transmittance so that an image can be read (exposed). The reference scale 19 has an end surface 19a (exposure reference position) extending in a direction orthogonal to the document feeding direction,
The edge of the supplied document is abutted.
The end surface 19a serves as a document positioning reference.

The reversing discharge section 4 includes a reversing roller 20, a reversing driven roller lower 21, a reversing guide claw lower 22, a reversing guide claw upper 23, a reversing driven roller upper 24, and a rotary encoder 2.
4a (control means), reverse sheet discharge switching claw 25, reverse sheet feeding guide 26, reverse registration sensor 27 (control means), switchback path 28, reverse inlet sensor 29 (control means),
Paper discharge path 30, paper discharge sensor 31 (control means), reverse jam detection sensor 32 (control means), paper discharge rollers 33a, 33
b. The reversing roller 20 is rotated by a servo motor (not shown). The lower reversing driven roller 21 contacts the reversing roller 20 and rotates, and cooperates with the reversing roller 20 to convey a document. The reverse guide claw 22 is the reverse roller 20.
And a pressing surface 22b having a curvature substantially equal to the external curvature of the reversing roller 20. When the rotation shaft 22a rotates, the reversing guide lower part 22 presses the document with the pressing surface 22b facing the reversing roller 20, and the document can be wound around the reversing roller 20. The reversing guide claw upper part 23 also has a rotating shaft 23a parallel to the rotating shaft of the reversing roller 20, and the tip end of the reversing guide claw upper part 23 is moved to the reversing roller 20 by rotating the rotating shaft 23a. Abut,
The document is wound around the reversing roller 20. The reversing driven roller upper part 24 contacts the reversing roller 20 and rotates, and cooperates with the reversing roller 20 to feed a document. A rotary encoder 2 is provided on the rotary shaft of the reversal driven roller 24 coaxially with the rotary shaft.
4a is arranged to generate a pulse in proportion to the rotation amount of the reverse driven roller 24 as the reverse driven roller 24 rotates. This pulse is output to the control unit as a signal corresponding to the rotation amount of the reverse driven roller 24. The reversal discharge switching claw 25 has a rotation shaft 25a parallel to the reversal roller 20. By rotating the rotation shaft 25a, the reversal discharge switching claw 25 is sandwiched between the reversal roller 20 and the reversal driven roller 24 and conveyed. It is possible to select whether to transport the received original to the transport unit 3 or the switchback path 28 described later. Reverse feeding guide 26
Is for guiding the document sent back to the transport unit 3 by selecting the reverse discharge switching claw 25 so that the document surely returns between the transport belt 15 and the contact glass 18. The reverse registration sensor 27 is used for the reverse feeding guide 2
When the document passes over 6 and the leading edge of the document crosses over the reversal registration sensor 27, a document detection signal is output. The switchback path 28, when the originals are selected to be discharged by the reverse discharge switching claw 25, when the originals are once drawn into the path and then sent back and discharged, the stacking order of the originals is set to the image forming apparatus main body. It is for adjusting when the manuscript is input. The reverse entrance sensor 29 outputs a detection signal to the controller when the leading edge of the document passes. The paper discharge path 30 is the switchback path 28.
This is for passing the document once drawn in and ejecting it to the outside of the apparatus. The paper discharge sensor 31 is used for the paper discharge path 3
The leading edge of the original that has passed 0 is detected and a detection signal is output to the controller. Reverse jam detection sensor 3
The switch 2 detects whether there is a document in the switchback path 28 and outputs a detection signal corresponding to the detection state to the control unit. Paper ejection rollers 33a, 33b
Is for discharging the document that has passed through the paper discharge path 30 to the outside of the apparatus.

Although not shown in detail in FIGS. 1 to 12, an image forming apparatus (main body apparatus) is provided below the contact glass 18. The control unit includes various sensor information such as the rotary encoder 11a, the size detection sensor 14, the rotary encoder 24a, the reverse registration sensor 27, the reverse entrance sensor 29, the paper discharge sensor 31, the reverse jam sensor 32, the driving roller 16, the reverse roller 20, and the like. Rotation information of each servo motor that rotates the pull-out drive roller 10, the rotation shaft 22 of the reversing guide claw 22
a, information about each rotating state of the rotating shaft 23a of the reversing guide claw 23, the rotating shaft 25a of the reversing sheet discharge switching claw 25, and the rotating shaft 22a of the reversing guide claw 22.
In order to rotate the rotating shaft 23a of the reversing guide claw 23 and the rotating shaft 25a of the reverse sheet discharge switching claw 25, and to drive the servo motors that rotate the drive roller 16 and the reversing roller 20, the respective members are driven. It outputs a command signal, and has a CPU (not shown), a memory such as ROM and RAM (document size storage means), an I / O circuit, a sequencer circuit, and the like.

The memory of the control unit stores the sizes of all the standard papers currently in circulation in the market, and also the end surface 1 of the registration sensor 13 and the reference scale 17.
7a, the reverse registration sensor 27 and the conveyor belt 15, the reverse jam detection sensor 32 and the reverse entrance sensor 29, and the like are stored in advance. Further, this memory can store all the sizes of the originals detected by the size detection sensor 14 and the pull-out driven roller 11 in the order in which the originals are fed, as long as the memory storage capacity allows, and they are detected sequentially. It is also possible to rewrite the memory of the original size.

This control unit conveys the preceding original document (not shown) by the conveyor belt 15 to the end surface 19a of the reference scale 19.
When the image forming apparatus finishes reading the image information, the conveyor belt 15 and the reversing discharge unit 4 are controlled based on the image information reading completion signal from the image forming apparatus to contact the preceding document. Glass 1
8 is conveyed to the reverse discharge unit 4 and is wound around the reverse roller 20 provided in the reverse discharge unit 4 to reverse the original surface, and then the original is returned onto the contact glass 18 and then the conveyor belt 15 of the conveyor unit 3. By rotating, the end face 19a of the reference scale 19 is again brought into contact with and positioned.

Then, the control section controls the pull-out driving roller 10 and the pull-out driven roller 11 to feed the sheet feeding section 2.
The leading edge of the document from the transport unit 3 to the registration unit 13
When it is detected by, the amount of rotation of the pull-out driven roller 11 is monitored from that point by counting the number of pulses of the rotary encoder 11a attached to the pull-out driven roller 11, and the amount of rotation is registered with the registration sensor 13 stored in advance as a reference. A command signal is output to the drive roller 16 so as to drive the conveyor belt 15 at a timing when the distance is equal to or substantially equal to the distance of the end surface 19a of the scale 19, and the preceding document is transferred to the end surface 19a of the reference scale 19. When the document is abutted and positioned, the following document (not shown) is brought into contact with or comes close to the preceding document, and two documents are rotated on the contact glass by rotating the conveyor belt 15. When the document is conveyed, the end of the following document is the reference scale 1.
9 is controlled so that it is brought into contact with the end surface 19a of 9 and positioned.

Further, the control unit rotates the conveyor belt 15 to convey the preceding document whose image has been read to the reversing and discharging unit 4, and wraps it around the reversing roller 20 of the reversing and discharging unit 4 to precede the document. And feed the inverted original document to the switchback path 28 once, reverse the reverse roller 20 to guide the preceding original document to the paper discharge path 30, and rotate the paper discharge rollers 33a and 33b. It is controlled so that it is discharged to the outside of the device. When the preceding document is wound around the reversing roller 20 and conveyed in the reversal discharge unit 4, when the reversing entrance sensor 29 detects the leading end of the preceding document, the rotation of the conveyor belt 15 is stopped, and only the preceding document is conveyed. Is conveyed in the reversing and discharging section 4, and the following original is controlled to be stopped on the contact glass 18. And
The preceding document is guided to the paper discharge path 30 and discharged, and when the reverse end sensor 29 detects the rear end of the document, the transport belt 15 is rotated again to guide the following document to the reverse discharge unit 4, and the reverse roller 20 is rotated. It is wound around and rotated so that the original surface is inverted and returned to the contact glass 18, and the conveyor belt 15 is rotated to make the succeeding original document again the reference scale 1.
The end surface 19a of the shaft 9 is controlled so as to be brought into contact with and positioned.

Further, the control unit controls the pullout driven roller 11 and the detection value of the width of the document detected by the size detection sensor 14.
The size of the succeeding document is determined from the number of pulses of the rotary encoder 11a attached to the memory and stored in the memory, and the size of the preceding document is read from the memory to determine a difference in size between the preceding document and the succeeding document. It is determined whether the difference is within the allowable amount, and if it is determined that the difference exceeds the predetermined allowable amount, a warning signal is transmitted to the main body device.

Further, the control unit is a reversal registration sensor 27.
When a detection signal is input from, the moving amount of the document calculated based on the number of pulses generated by the rotary encoder 24a attached to the rotating shaft of the reverse driven roller 24 is monitored, and the reverse registration sensor 27 stored in advance is monitored. The drive roller 1 rotates the conveyor belt 15 in the normal direction when the distance between the conveyor belt 15 and the conveyor belt 15 approaches or becomes equal.
6, the control unit controls the reverse entrance sensor 29
It is possible to determine that the document has been sent to the reversal discharge unit 4 by the document detection signal of, and based on the detection signal,
The rotation of the conveyor belt 15 can be controlled.

Further, when the control unit receives the detection signal from the paper discharge sensor 31, the control unit can rotate the paper discharge rollers 33a and 33b based on the detection signal to discharge the original and detect the reverse jam. Based on the detection signal from the sensor 32, it corresponds to either one of the case where the original is not sent into the switchback path 28 and the case where the original is sent but the original does not move even after a lapse of a predetermined time. It is determined whether or not there is one, and when it is determined that one of them is applicable, a warning signal is output to the main body device to notify the main body device that a paper jam has occurred in the reversal discharge unit 4. It is like this.

Next, the operation will be described. The first document 50 (preceding document) separated by a document separation unit (not shown) is conveyed in the paper feed path 12 by the pull-out driving roller 10 and the pull-out driven roller 11, and is conveyed to the conveyance unit 3. At this time, when the size detection sensor 14 arranged in the direction orthogonal to the document feeding direction detects the size of the first document 50 in the width direction, the detected value is output to the control unit and the pull-out follower is driven. The rotary encoder 11a attached to the roller 11 outputs a pulse to the control unit. Next, from the detection value of the size detection sensor 14 and the number of pulses from the rotary encoder 11a,
The control unit determines the document size. Next, the size of the first original 50 is stored in the memory in the control unit.

The first original 50 is fed from the paper feeding unit 2 to the conveying unit 3.
When the document 50 is conveyed to the contact glass 18, the first document 50 is once fed in the feeding direction, and the entire longitudinal direction of the document is fed onto the contact glass 18, and then the conveyance belt 15 is rotated in the opposite direction. The eye original 50 is abutted against the end surface 19a of the reference scale 19 and positioned (see FIG. 2). When the first document 50 is positioned and the image reading unit of the image forming apparatus (not shown) reads the image information of the first document 50, the reversing guide nail 22 moves the rotary shaft 22a clockwise in FIG. While rotating as the central axis, the reversing guide claw upper 23 rotates counterclockwise in FIG. 2 about the rotating shaft 23a as a central axis to secure a path for reversing the first original 50 by the reversing roller 20. To do. When the document reversing path is secured, the conveyor belt 15 rotates in the normal direction and sends the first document 50 to the reversing and ejecting section 4. When the first document 50 is fed to the reversal discharge unit 4, the reversal roller 20 rotates clockwise in FIG. 2, and the reversal roller 20 cooperates with the lower reversal driven roller 21 which is opposed to While feeding the first original 50, the first original 50 is reliably engaged with the reverse roller 20 by the reverse guide claw lower part 22 and the reverse guide claw upper part 23 (see FIG. 3). The first original 50 wound around the reversing roller 20 is fed by the reversing driven roller upper 24 to the feeding unit 3 and fed back. The first original 50 whose original surface has been inverted in this manner follows the reverse feed guide 26 and faces the transport unit 3. When the reverse registration sensor 27 detects that the leading edge of the first original 50 has passed, after detecting the leading edge, the conveyor belt 15 is reversed at the above-described predetermined timing, and the first original 50 is contact glass again. 18
It is conveyed upward (see FIG. 4). Reversed original 5
0 is conveyed on the contact glass 18 by the conveyor belt 15 which rotates in the reverse direction, and the end surface 19a of the reference scale 19 is conveyed.
Then, it is stopped and positioned (see FIG. 5). When the positioning of the inverted first original 50 is completed, the second original 51 (following original) is separated from the paper feeding unit 2 by the original separating unit and is supplied by the pullout drive roller 10 and the pullout driven roller 11. To be done. At this time, the control unit determines the size of the second document 51 from the detection value detected by the size detection sensor 14 and the number of pulses from the rotary encoder 11a, stores the size in the memory, and stores the size of the first document 50. Is read from the storage unit, and it is determined whether or not the size difference between the first document 50 and the second document 51 is within a predetermined allowable amount. If it is determined that there is a second document 51, the second document 51 is fed to the transport unit 3 as it is, but if it is determined that the difference exceeds a predetermined allowable amount, a warning signal is transmitted to the main body device. . For example, when it is determined that the size of the preceding document is A4 size and the size of the following document is A3, a warning signal is transmitted to the main body device, but the preceding document is A4 size and the following document. When the size of A is an intermediate size between A4 and B5, the predetermined work may be continued as it is, or a warning signal may be transmitted to the main body device. Further, for example, when the size of the preceding document is A4 size and the size of the following document is B5, the predetermined work may be continued or a warning signal may be transmitted to the main body device. The following description is for the case where the size difference between the following originals is within a predetermined allowable amount.

When the second original 51 is fed to the conveying section 3, the front end of the second original 51 is contacted with the contact glass 1.
8, the conveyor belt 15 is rotated in the forward direction in synchronization with the end of the first original 50 that is stopped by being abutted against the end surface 19a of the reference scale 19 on the upper side. As the timing at which the edge of the first document 50 and the edge of the second document are juxtaposed without a gap, the distance between the registration sensor 13 and the end surface 19a of the reference scale 19 is stored in advance as described above. Therefore, the registration sensor 13 causes the second original 51
When the leading end of the second original 51 reaches the end face 19a of the reference scale 19 with sufficient accuracy by detecting the leading end of the sheet and monitoring the amount of rotation of the pull-out driven roller 11 from the time when it is detected. Therefore, the first original 50 and the second original 51 can be brought close to each other by a predetermined distance or brought into contact with each other. The first original 50 and the second original 51 are moved side by side on the contact glass 18 in a juxtaposed state, and are transferred until the end of the second original 51 passes the end 19a of the reference scale 19. Then, the conveyor belt 15 is rotated in the reverse direction to move the two side-by-side originals backward.
It is moved backward until the end of 1 abuts against the end 19a of the reference scale 19. When the positioning of the two side-by-side originals is completed (see FIG. 6), image reading is performed, and the back side image information of the first original 50 and the second original 5 are read.
One surface image information is read at a time. When the reading of the image information is completed, both the reverse guide claw lower part 22 and the reverse guide claw upper part 23 do not rotate and maintain the same posture, but the reverse sheet discharge switching claw 25 rotates counterclockwise. ,
The function of the reverse discharge unit 4 is switched to the discharge function. When the switching of the reverse sheet discharge switching claw 25 is completed, the transport belt 15 rotates in the forward direction to transfer the juxtaposed documents toward the reverse sheet discharge unit 4.
The first original 50 is wound around the reversing roller 20 and conveyed in the reversal discharge unit 4, and when the leading edge of the first original reaches the reversal entrance sensor 29, the conveyance belt 15 is rotated normally. Stop. As a result, only the first original 50 is fed to the reversal discharge unit 4, and the second original 51 remains on the contact glass 18. Inversion discharge part 4
The first original 50 fed into the paper is wound around the reversing roller 20 and passes through the contact portion with the reversing driven roller upper 24,
It is sent to the switchback path 28 by the reverse discharge switching claw 25 (see FIG. 7). When the reverse entrance sensor 29 detects the rear end of the first document 50, the reverse guide claw 23
Is rotated clockwise and the rotation of the reversing roller 20 is stopped. Next, the reversing roller 20 is rotated in the reverse direction, the first document 50 fed into the switchback path 28 is sent out to the paper discharge path 30, and the paper discharge rollers 33 a, 3
3b is rotated to eject the first document 50 outside the apparatus (see FIG. 8). It should be noted that in the second original 51, the first original 50 is wrapped around the reversing roller 20 and the first original 5
When the leading edge of 0 reaches the reversal entrance sensor 29, the rotation of the conveyor belt 15 is stopped and remains on the contact glass 18, and the first original 50 is switched back to the switchback path 28.
Is switched back from, and is discharged through the discharge path 30.
It waits on the contact glass 18 until the rear end of the first document 50 comes into contact with the reverse entrance sensor 29. When the trailing edge of the first document 50 passes over the reversing entrance sensor 29, the reversing guide claw upper part 23 rotates counterclockwise, and the reversal discharge switching claw 25 rotates clockwise, thereby reversing the path. Secure. When the reversing path is secured, the conveyor belt 15 rotates in the forward direction, and the second document 51 is sent to the reversing and discharging section 4 to reverse the document (see FIG. 9). The second document 51, the front surface and the back surface of which are reversed, follows the reversal feeding guide 26 toward the conveyance unit 3. When the reverse registration sensor 27 detects that the leading edge of the second document 51 has passed, after the leading edge is detected, the conveyor belt 15 is rotated in reverse at the above-described predetermined timing, and the second document 51 is contact glass again. 1
8 (see FIG. 10). The inverted second original 51 is conveyed on the contact glass 18 by the conveyor belt 15 that rotates in the reverse direction, and the end surface 1 of the reference scale 19 is conveyed.
It abuts against 9a, is stopped, and is positioned. When the positioning of the inverted first original 50 is completed, the second original 51 (following original) is separated from the paper feeding unit 2 by the original separating unit and is supplied by the pullout drive roller 10 and the pullout driven roller 11. (See FIG. 11). At this time, the control unit determines the third original 52 based on the detection value detected by the size detection sensor 14 and the pulse number of the rotary encoder 11a mounted on the pullout driven roller 11.
The size of the second document 50 is read out from the storage unit, and the size difference between the second document 51 and the third document 52 is within a predetermined allowable amount. If it is determined that the difference is within a predetermined allowable amount, the third document 5 is directly processed.
2 is fed to the transport unit 3, but if it is determined that the difference exceeds a predetermined allowable amount, a warning signal is transmitted to the main body device. When the third original 52 is fed to the conveyance unit 3, the leading end of the third original 52 is abutted against the end surface 19a of the reference scale 19 on the contact glass 18 and stopped. The conveyor belt 15 is rotated in the forward direction in synchronization with the arrival of the end of the original document 51. Second original 5
The synchronization timing at which the edge of 1 and the edge of the third document are juxtaposed without a gap is the same as that described above. The second original 51 and the third original 52 are moved side by side on the contact glass 18 in a juxtaposed state, and are moved until the end of the third original 52 passes the end 19a of the reference scale 19. After that, the conveyor belt 15 is rotated in the reverse direction to move the two side-by-side originals backward, until the end of the third original 52 abuts against the end 19a of the reference scale 19. To be When the positioning of the two side-by-side originals is completed (see FIG. 12), image reading is performed, and the back-side image information of the second original 51 and the front-side image information of the third original 52 are read at once. To be Thereafter, the "2-in-1" image of the double-sided original is similarly formed.

When the final original 53 is reached, the front surface of the final original 53 is "2 in 1" image-formed with the back surface of the original one before the final original 53, and 1
After the original document is ejected, it is inverted by the reversal ejection unit 4, conveyed again on the contact glass 18, and abutted against the end surface 19a of the reference scale 19 to be positioned (see FIG. 2). After the last document 53 is positioned,
If the registration sensor 13 does not detect the next document after the elapse of the predetermined time, the control unit determines that the last document 53 is the last sheet, and the image forming apparatus reads the image information only on the back surface of the last document 53. FIG. 13 shows the correspondence relationship between the copy image read by the image forming apparatus in this manner and the image of the original fed on the contact glass 18 of the automatic original feeding apparatus 1.

As described above, in the present embodiment, the preceding original 50 is conveyed to the end surface 19a of the reference scale 19 by the conveying belt 15 and positioned, the image information of the original is read, and then the preceding original 50 is read. Is reversed and returned to the contact glass 18 again for positioning, and the following original document 51 is fed and the preceding original document 50 is fed.
And the succeeding original 51 are brought into contact with or close to each other, and the two originals are conveyed and juxtaposed on the contact glass 18 so that the succeeding original 51 is positioned on the end surface 19a of the reference scale 19. The rear surface of the original 50 to be printed and the front surface of the following original 51 can be presented to the image forming apparatus side by side with a spread, and even if the original is a double-sided original, the image can be easily imaged without disturbing the page order of the two originals. The forming device can form a "2 in 1" image on one sheet of transfer paper.

Further, the preceding document 50 that has been exposed is conveyed to the reversing and discharging unit 4, and is reversed and discharged by the reversing and discharging unit 4, and the preceding document 50 is reversed and discharged. At this time, the succeeding original 51 is allowed to stand by on the contact glass for a predetermined time, and then the conveyor belt 18
Further, since the following original 51 is reversed by the reversing roller 20 and returned to the contact glass 18 and positioned again on the end surface 19a of the reference scale 19, the discharged original is the same page order as the page placed on the original table. It is possible to stack the documents in order, which does not cause any trouble in handling the originals, and to perform the two processes of the former reversal discharge process and the latter reversal process on the preceding document 50 and the following document 51 arranged side by side. It can be performed quickly and stably. Moreover, since the mechanism for reversing processing and the mechanism for discharging are shared, the mechanism can be simplified, the reliability of the apparatus is improved, and a low cost automatic document feeder 1 is provided. You can

If the control unit compares the size of the preceding document with the size of the succeeding document 51 and determines that the document sizes differ by more than a predetermined allowable amount, the result of the determination is Based on this, the control unit sends a warning signal to the main body device before the exposure is started, so that it is possible to know that the size of the document is uneven before the image information of the document is read.
It is possible to prevent image loss and image formation which is not desired by the operator due to the non-uniformity of the image area of the document and the exposure area of the image forming apparatus.

[0033]

According to the first aspect of the invention, the preceding document is conveyed to the exposure reference position by the conveying means and positioned, and then the image information of the document is read, and then the preceding document is reversed. And return it to the contact glass for positioning, feed the subsequent original, and bring the original and the following into contact with or close to each other.
Then, the two originals are conveyed and juxtaposed on the contact glass so that the succeeding original is positioned at the exposure reference position, so that the back side of the preceding original and the front side of the following original can be arranged side by side with a spread. Even for a double-sided original, the image forming apparatus can easily form a “2 in 1” image on one transfer sheet without disturbing the page order of the two originals. According to the second aspect of the present invention, the preceding document which has been exposed is conveyed to the reversing and ejecting means, the reversing and ejecting means reverses and ejects the original, and the preceding original is reversed and ejected. At this time, the succeeding original document is made to stand by on the contact glass for a predetermined time, and then the succeeding original document is reversed by the transporting means and the reversing and returning hand and returned on the contact glass to be positioned at the exposure reference position again, so that it is ejected. The originals can be stacked in the same page order as they were placed on the original table, there is no trouble in handling the originals, and the former is reversed with respect to the preceding and succeeding originals arranged in two. It is possible to quickly and stably perform the two processes of the discharging process and the latter reversing process. Moreover, since the mechanism for reversing processing and the mechanism for discharging are shared, the mechanism can be simplified,
It is possible to improve the reliability of the apparatus and provide a low-cost automatic document feeder.

According to the third aspect of the present invention, the determining means compares the preceding document size with the following document size and determines that the document size has a difference exceeding a predetermined allowable amount. In this case, since the warning means sends a warning signal to the main body device before the exposure is started based on the judgment result of the judgment means, it is possible to know the irregular size of the manuscript before the image information of the manuscript is read. In addition, it is possible to prevent the loss of an image due to the non-uniformity between the image area of the original and the exposure area of the image forming apparatus and the image formation which is not desired by the operator.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an embodiment of an automatic document feeder according to the present invention.

FIG. 2 is a diagram showing how the first original is positioned in one embodiment.

FIG. 3 is a diagram showing a manner in which a first original is reversed in one embodiment.

FIG. 4 is a diagram showing a manner in which a first original is reversed and returned onto a contact glass in one embodiment.

FIG. 5 is a diagram showing a state in which a first document is positioned on a contact glass and then a second document is fed in one embodiment.

FIG. 6 is a diagram showing a manner in which a first original and a second original are juxtaposed on a contact glass in one embodiment.

FIG. 7 is a diagram showing a manner in which a first original is fed into a switchback path in one embodiment.

FIG. 8 is a diagram showing a manner in which the first original document is discharged to the outside in one embodiment.

FIG. 9 is a diagram showing a state in which a second document is reversed in one embodiment.

FIG. 10 is a diagram showing a state in which the second original is reversed and returned onto the contact glass in one embodiment.

FIG. 11 is a diagram showing how a third document is fed in one embodiment.

FIG. 12 is a diagram showing a manner in which a second original and a third original are arranged side by side on a contact glass in one embodiment.

FIG. 13 is a diagram showing a correspondence relationship between a copy image formed by the image forming apparatus according to the embodiment and an image of a document fed on the contact glass.

[Explanation of symbols]

1 Automatic Document Feeding Device 2 Paper Feeding Unit (Paper Feeding Unit) 3 Conveying Unit (Conveying Means) 4 Reversing Ejecting Unit (Reversing Returning Means, Reversing Ejecting Means) 11a Rotary Encoder (Controlling Means, Document Size Detecting Means) 13 Registration Sensor (Control means) 14 Size detection sensor (original size detection means) 18 Contact glass 19a End surface of reference scale (exposure reference position) 24a Rotary encoder (control means) 27 Reverse registration sensor (control means) 29 Reverse entrance sensor (control means) 31 Paper Ejection Sensor (Control Means) 32 Reversed Jam Detection Sensor (Control Means) 50 First Original (Preceding Original) 51 Second Original (Subsequent Original)

Claims (3)

[Claims] 1. A document placing table on which a document bundle made up of a plurality of documents can be placed, and a sheet feeding means for separating and feeding the lowest document from the document bundle on the document placing table one by one. The document fed from the sheet feeding means is conveyed and positioned at the exposure reference position on the contact glass, and then the document after the document exposure is driven in one direction so as to be carried out from the contact glass and is also returned. To the exposure reference position on the contact glass again, and a conveying means that can be driven in the other direction so as to be positioned, and the original surface of the original that is conveyed from the contact glass by the conveying means is reversed and again on the contact glass. And an inversion return means for returning to the contact glass, and 2 on the basis of the exposure reference position on the contact glass.
And a control means for controlling the paper feeding means, the conveying means and the reversing and returning means so as to arrange a plurality of originals side by side, wherein the control means conveys the preceding original document to the exposure reference position by the conveying means, After the positioning, when the exposure of the original is completed, the conveying means and the reversing and returning means are controlled so that the original is reversed and returned to the contact glass to be positioned at the exposure reference position again, and the paper feeding means is controlled. Then, the following original is fed onto the contact glass and brought into contact with or close to the preceding original, and then the feeding means and the feeding means are controlled to convey and position the following original to the exposure reference position. Thus, the automatic document feeder, wherein the two documents are arranged side by side on the contact glass. 2. A reversing and discharging unit for reversing a document surface of a document carried out from the contact glass by the transporting unit and discharging the document to the outside of the apparatus, wherein the control unit controls the transporting unit to finish the exposure. The original document is conveyed to the reversal ejection unit, and the reversal ejection unit is controlled to invert and eject the original document. When the preceding original document is inverted and ejected, the succeeding original document waits on the contact glass for a predetermined time. 2. The automatic document feeder according to claim 1, further comprising the step of controlling the conveying means and the reversing and returning means to invert the following original to return it to the contact glass and position it at the exposure reference position again. Sending device. 3. A document size detecting means for detecting a document size fed on a contact glass and outputting it as a document size detection value, and a document size storage for storing the document size detection value output by the document size detecting means. Means for comparing the size of the preceding document and the size of the following document to determine the difference between the sizes of the two, and warning means for transmitting a warning signal to the main body device. The determination means compares the preceding document size stored in the document size storage means with the document size of the subsequent document detected by the document size detection means, and the difference in document size exceeds a predetermined allowable amount. 2. The automatic source according to claim 1, wherein, when it is determined that it is the one, the warning means transmits a warning signal to the main body device before the exposure is started based on the judgment result of the judgment means. Paper feeding device.