JP2001354339A - Automatic document feeding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify and miniaturize the structure of a document part in an automatic document feeding device capable of reading both sides of a document by reversing the front and rear sides of the document and feeding the document again to an image reading position after automatically feeding the document to the image reading position. SOLUTION: The automatic document carrying device has a conforming means mounted on the upstream side of a document reading position in a feeding passage for conforming the top of the document fed by the device to the feeding passage. The conforming means conforms the document fed from a document feed passage for reading one side of the document and also conforms the front/rear reversed sheet fed from a reversed document feed passage for reading the other side of the document. The confirming means is comprised of a pair of resisting rollers, whose rotation for feeding the document and the stop of the rotation for the conformation are controlled. The conformation of the document is operated by making the document butt at a nipping point of the resisting rollers.

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 in an image reading apparatus, and more particularly to an automatic document feeder which automatically feeds a document to an image reading position, reverses the front and back, and feeds the document to the image reading position again. The present invention relates to an automatic document feeder for reading both sides of a document.

[0002]

2. Description of the Related Art In an automatic document feeder used in an image forming apparatus such as a copying machine, a facsimile, an image scanner, etc., one or more documents placed on a paper feed tray are automatically supplied to an image reading section, and an image is read. After the reading process is completed, the document is automatically ejected to the output tray.
A registration unit for optimizing the skew of the document is provided in a conveyance path from the sheet feeding tray to the image reading unit. In other words, a pair of rollers is provided in the transport path from the paper feed tray to the image reading unit, and the leading edge of the original is abutted by a predetermined amount while the pair of rollers is stopped to correct the inclination in the original transport direction. There is provided a resist means for performing the above.

A conventional automatic document feeder has been proposed which can read images on both sides of a document as shown in FIG. 26, for example. This means that the original sent from the paper feed tray 100 is transported to a large transport
Reading means 11 of the image reading apparatus main body 110
Conveyed to the document reading unit 102 facing the document reading unit 1
02, the reading means 111 reads the surface of the document, and then a switchback path 103 provided downstream thereof.
The original is reversed by using, and the back side of the original is read by being conveyed again on the peripheral surface of the conveying roller 101, and further, the original whose front and back sides have been read is switched back in order to align the page order when the original is discharged. In some cases, the document is inverted from the path 103 via the document reading unit 102 and discharged onto the discharge tray 104.

In this automatic document feeder, a paper feed tray 1
The original fed from 00 is abutted against a pair of rollers 106 by a paper feed roller 105 arranged on the upstream side to correct the original.
The roller 1 pressed against the transport roller 101 by the switchback roller 108 during the transport from
The original is corrected by abutting the leading end of the original at 07.

[0005]

However, in the above-described conventional automatic document feeder, the document fed from the paper feed tray 100 and the switchback path 103 after the front face is read by the document reading unit 102 are read. The position for correcting a document re-fed to the document reading unit 102 via the document feeder is separately provided, so that the paper feeding path is lengthened, the apparatus is enlarged, and the structure is complicated.

Accordingly, an object of the present invention is to provide a small-sized automatic document feeder having a simplified configuration.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is directed to an image forming apparatus for reading images on both sides of a document sheet to be conveyed one by one using a reading device arranged on one side of a conveyance path of the document sheet. An automatic document feeder for sequentially reading, provided with an aligning means provided upstream of a transport path at a reading position of the original sheet and aligning a leading end of the supplied original sheet with the transport path; Receives and aligns the original sheet from the original sheet supply path to read one side, and reads the other side of the original sheet which has been turned upside down via the reading device. It is an object of the present invention to provide an automatic document feeder having a function of receiving the front and back reversed sheets from a sheet supply path and aligning them.

Here, the aligning means may be constituted by a pair of registration rollers in which rotation for conveying the original sheet and rotation stop for performing the alignment are controlled.

At the same time, the alignment of the original sheet can be performed by abutting the original sheet on the nip point of the pair of registration rollers.

Further, the original sheet supply path and the reverse original sheet supply path may be configured to merge at a position upstream of a nip point of the pair of registration rollers.

In addition, a guide member for guiding the leading end of the document sheet to the nip point of the pair of registration rollers can be provided between the document sheet supply path and the inverted document sheet supply path.

On the other hand, the original sheet is conveyed by using a first drive motor and a second drive motor as a drive source, and the first drive motor rotates in the forward direction so that the original sheet in the original sheet supply path is moved. A sheet feed roller for conveying a sheet is driven, and the registration roller is driven by rotation in a reverse direction. The second drive motor includes a conveyance roller for passing the original sheet through the reading device, and a supply of the inverted original sheet. The reversing roller for transporting the reversing original sheet on the road can be configured to be driven forward and reverse.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a view showing an automatic document feeder mounted on an image reading apparatus according to the present invention, and FIG. 2 is a view showing a main part of the automatic document feeder.

In FIG. 1, reference numeral 10 denotes an automatic document feeder mounted on the image reading apparatus main body 1. The automatic document feeder 10 conveys the original so as to pass over the upper surface of the contact glass 2 of the apparatus main body 1. It has become. The apparatus body 1 is provided with a light source 3 such as a lamp via a contact glass 2.
Then, light from the original is irradiated onto the conveyed document, and the reflected light is reflected by the mirror 4 to read the image of the document sheet photoelectrically converted by reading means such as a CCD. That is, the upper surface of the contact glass 2 constitutes a reading unit of the apparatus main body 1. The apparatus main body 1 also includes a contact glass 5 having an area on which a document can be placed. The document placed on the upper surface of the contact glass 5 by opening and closing the automatic document feeder 10 includes a light source 3 and a mirror 4. By moving the light source unit in the sub-scanning direction, the image on the document sheet can be read through the contact glass 5.

The automatic document feeder 10 includes a paper feed tray 15 on which a plurality of document sheets can be placed, and a paper feeder for separating the documents on the paper feed tray 15 one by one and feeding them toward the contact glass 2. A feeding unit (feeding unit) 11, a feeding unit 12 for passing a document sheet along the upper surface of the contact glass 2,
A discharge unit 13 that receives and discharges a document sheet that has passed through the upper surface of the contact glass 2, and a discharge tray 16 that stores a document on which an image discharged from the discharge unit 13 is read.
And

The document feeder 10 further includes a discharge unit 1 for a document sheet discharged from the upper surface of the contact glass 2.
3 is switched back, and is sent back to the feeding unit 11 to be fed back to the upper surface of the contact glass 2.
4 is provided. Here, the document tray 15 is inclined at a certain angle, and is arranged above the paper discharge tray 16 with a space secured.

The original sheet placed on the paper feed tray 15 is regulated by a side guide 17 which regulates a side portion thereof.
The tip is regulated by the stopper 60. The paper feed tray 15 is rotatably mounted around a leading end 15a of the placed original sheet as a fulcrum.

The feeding section 11 is lowered to come into contact with the uppermost surface of the original on the paper feed tray 15 and is capable of moving up and down to feed the original, and a feed roller for feeding the original fed by the feeding roller 18. 19 and a separation pad 20 which passes only one sheet of the uppermost document and stops feeding of the second and subsequent documents, and pushes the leading end of the document separated by this separation means into one sheet. The registration roller pair 21 is fed to the downstream side after the contact and alignment, and feeds the original sheet along the paper feed path 25.

The transport section 12 includes a pair of transport rollers 22 for supplying the original sheet to the contact glass 2 on the upstream side of the contact glass 2 and a pair of transport rollers 23 for discharging the original sheet from the contact glass 2 on the downstream side. Yes,
The document sheet is transported along a transport path 26 formed by the contact glass 2 and the pick-up guide 6 on the main body 1 side and the backup guide 26a on the automatic document feeder 10 side.

The discharge unit 13 and the switchback unit 14 share a part on the paper discharge tray 16 side, and are provided with a paper discharge roller pair 24 for discharging a document to the paper discharge tray 16. As described later, the discharge roller pair 24 is controlled so as to rotate in the reverse direction with the rear end side of the document nipped in the double-sided mode, switch back the document, and send the document to the discharge unit 13.
Further, the paper discharge roller pair 24 is driven from the paper discharge drive roller 24a to the paper discharge driven roller 24b so that when the front and rear ends of the document circulated from the switchback unit 14 through the discharge unit 13 and the transport unit 11 pass each other, there is no problem. Are configured to be separated from each other. A flapper 29 that guides the document sheet to the discharge unit 13 is provided in a shared portion of the discharge unit 13 and the switchback unit 14. This flapper 29
When the original is sent to the pair of paper ejection rollers 24 along the paper ejection path 27, the original is pushed upward by the leading end of the original to be ejected. When the original is allowed to pass through, and the original is switched back by the discharge roller pair 24, the lower position is closed and the discharge path 27 is closed.
The document is guided to the switchback path 28.

The paper discharge path 27 is formed by a paper discharge upper guide 27a provided with a backup guide 26a provided to face the contact glass 2 and a paper discharge lower guide 27b integrally formed with the paper discharge tray 16. The switchback path 28 is formed so as to guide the document to the nip point of the registration roller pair 21 by the lower switchback guide 28b and the upper switchback guide 28a provided continuously on the document guide surface of the flapper 29. ing.

That is, the switchback path 28 and the sheet feeding path 2
5 is configured to merge at the nip point of the registration roller pair 21. The original sheet fed through the paper feed path 25 and the original sheet fed through the switchback path 28 and re-fed are registered with the registration rollers. Each pair 21 is matched. Thus, the alignment position of the original sheet (registration roller pair 2
By sharing 1), the document feed path of the entire apparatus is simplified and compact, and the document transport control can be simplified.

The switchback path 28 and the paper feed path 25
Is configured so that they merge at the nip point of the registration roller pair 21, so that the paper supply path 25 from the paper supply roller 20 to the registration roller pair 21 and the switchback path 28 from the flapper 29 to the registration roller pair 21 are substantially formed. Since the document can be formed in a straight line, the document is smoothly guided by the pair of registration rollers 21 and the document is aligned without applying stress to the document, so that appropriate skew can be removed.

Further, the registration roller pair 2
Since the Mylar 28c that guides the original is extended at the nip point 1, the original sheet fed through the paper feed path 25 and the original sheet fed through the switchback path 28 and re-fed can be used. It will be surely guided to the nip point of the registration roller pair 21 and will be surely aligned.

Here, as shown in FIG. 3, the paper feed path 25 is formed with an upper guide plate 25a and a lower guide 25b facing each other, and the upper guide plate 25a is rotatably supported by a rotation fulcrum 10c. It can be opened and closed by being fixedly mounted on the outer cover 10a and integrally rotated counterclockwise. The outer cover 10a includes a feed roller 18, a paper feed roller 19, and a pair of registration rollers 2.
One driven roller 21b is provided so as to rotate integrally.

The upper switchback guide 28a is
As shown in FIG. 4, it is formed integrally with the paper feed lower guide 25b, and the integrated guide is supported so as to be able to rotate clockwise around the rotation axis of the paper discharge drive roller 24a. Note that the switchback upper guide 28a and the paper feed lower guide 25
The separation pad 20 and a biasing spring 20a of the separation pad 20 are attached to the guide integrated with the b and are integrally rotated.

Next, the drive configuration of each roller is shown in FIG.
This will be described with reference to FIG. The automatic document feeder 10
Is configured to drive each roller by a feed motor M1 and a transport motor M2 that can be rotated forward and backward. FIG. 5 shows a drive transmission system of the feed motor M1, and FIG. FIG.

First, as shown in FIG. 5, the drive transmission system of the paper feeding motor M1 is such that the normal rotation driving of the paper feeding motor M1 is performed by the pulley P1.
6 to the pulley P36 via the timing belt T16, and the pulley P36 is driven by the gear Z17 and the gear Z1.
9. Gear Z1 attached to the drive shaft of paper feed roller 19
8, the paper feed roller 19 rotates in the direction of feeding the original. A pulley P18 is provided on the drive shaft of the paper feed roller 19, and the pulley P18 is also driven via a timing belt T2 stretched between the pulley P11 provided on the shaft of the feed roller 18. Is transmitted.

One end of an elevating arm 18a for supporting the feeding roller 18 is attached to the driving shaft of the paper feeding roller 19, and the rotation of the driving shaft in the paper feeding direction (the forward rotation of the paper feeding motor M1). ), The raising / lowering arm rotates and the feeding roller 18 descends, and when the feeding roller comes into contact with the original, the drive shaft of the paper feed roller 19 idles with respect to the lifting arm 18a by the action of the spring clutch A and the spring clutch B. It is configured as follows. At this time, the registration drive roller 21a is connected to a pulley P2 provided on its drive shaft.
8 is connected to a pulley P22 provided coaxially with the pulley P36 by a timing belt T3 stretched over a pulley P22.
It does not rotate due to the action of W1.

The reverse rotation of the feed motor M1 is controlled by the pulley P1.
6 to the pulley P36 via the timing belt T16, and the pulley 22 provided coaxially with the pulley P36.
To the pulley P28 attached to the shaft of the registration drive roller 21a via the timing belt T3,
The registration drive roller 21a is rotated in the sheet feeding direction. At this time, the reverse rotation drive of the feed motor M1 is also transmitted to the drive shaft of the feed roller 19, and the feed roller is raised by rotating the elevating arm 18a counterclockwise.
The paper feed roller 19 does not rotate due to the action of the one-way clutch OW2 provided therein. The raised lifting arm comes into contact with a regulating member (not shown), and the drive shaft of the sheet feeding roller 19 is configured to idle with respect to the lifting arm 18a by the action of the spring clutch C.

In such a configuration, the feed roller 19
The gear Z18 attached to the drive shaft is arranged on the outer cover 10a together with the feeding roller 18 and the paper feed roller 19 so that the gear Z18 rotates integrally with the outer cover 10a. The path 25 is separated from the gear Z19 by opening, and meshes with the gear Z19 by closing.

Next, as shown in FIG. 6, the drive transmission system of the transport motor M2 transmits the drive from the pulley P26 provided on the drive shaft to the pulley P46 via the timing belt T4, and the drive transmission system is coaxial with the pulley P46. Provided pulley P33
From the transport drive roller 23 via the timing belt T6
The drive is transmitted to the pulley P32 attached to the shaft a, and the transport drive roller 23a is rotated forward or backward.
Further, the drive transmitted to the pulley P32 is configured such that the drive is transmitted to the pulley P31 attached to the shaft of the transport drive roller 22a via the timing belt T7, and the transport drive roller 22a is rotated forward or backward. Have been. Also, the pulley P4 is connected via the timing belt T4.
6 is transmitted to the pulley P46.
The drive is transmitted from the pulley P42 provided coaxially to the pulley P48 attached to the shaft of the paper discharge drive roller 24a via the timing belt T5, so that the paper discharge drive roller 24
a is rotated forward or backward.

Further, a pressure solenoid SOL is provided as a drive source for separating the sheet discharge roller pair 24.
The press-contact solenoid SOL excites (turns on) the press-contact solenoid SOL to move the discharge driven roller 24b to a position where it presses against the discharge drive roller 24a, and releases the excitation (turns off) so that the discharge driven roller 24b is released. Is driven by the action of an urging spring that urges the paper discharge drive roller 24a away from the paper discharge drive roller 24a.
It is configured to be moved to a position away from a.

As shown in FIG. 1, the original tray 15 is provided with a plurality of sensors S1, S2, S3 in the original feeding direction, and the ON-O of these sensors S1, S2, S3.
The length of the document placed on the document tray is detected based on the FF state. Further, the width direction of the document sheet placed on the document tray 15 is detected from a volume (not shown) whose output changes according to the movement amount of the side guide 17, and the detection result of the document width and a plurality of sensors S1, The document size is determined based on the length of the document sheet detected in S2 and S3.

An empty sensor S4 for detecting that a document has been placed on the document tray 15 is provided downstream of the document tray 15 in the document feeding direction. A registration sensor S5 for detecting the end of the original sheet fed through the paper feed path 25, a lead sensor S6 provided in front of the contact glass 2 for detecting the end of the original sheet, and an original sheet discharged from the contact glass 2 Are respectively provided. Note that all sensors including a registration sensor S5, a lead sensor S6, and a discharge sensor S7 for detecting a document sheet sent in the path are connected from the paper feed path 25 to the transport path 2
6. It is arranged in a space inside a lube-shaped path that returns to the transport path 26 again via the sheet discharge path 27 and the switchback path 28. Accordingly, it is not necessary to secure a space for mounting the sensor, and the device can be downsized.

Here, the registration sensor S5 employs a lever-type sensor as shown in FIG. 7, and the sensor lever S5a of this sensor is connected to the paper feed path 25 and the switchback path 2.
8 are arranged to protrude in both paths. With this configuration, since both the original sent through the paper feed path 25 and the original sent through the switchback path 28 are detected by one sensor, the number of sensors used as an apparatus can be reduced. I have. In the present embodiment, a lever type sensor is employed as a sensor for detecting a document fed through the paper feed path 25 and the switchback path 28. However, a document of both paths can be detected using a transmission type sensor.

These sensors S1 to S7 are connected to a CPU that controls the driving of the entire apparatus, and based on detection signals from the sensors, the above-described motors M1, M2
Is driven, and the press-contact solenoid SOL is excited.

Next, the document transport control operation of the automatic document feeder having the above configuration will be specifically described with reference to the flowcharts shown in FIGS. Reference is made to FIGS. 22 to 25 which schematically show the conveyance state of the document sheet as necessary.

First, a one-sided mode for reading one side of a document will be described with reference to FIGS.

When the empty sensor S4 is in the ON state, that is, when it is detected that a document sheet is placed on the paper feed tray 15, the paper feed motor M1 is driven to rotate forward to feed the first document D1. (S1 and S2). At this time, the feed roller 18 and the paper feed roller 19 are rotated in the document feeding direction, but the registration roller pair 21 is not rotated by the action of the one-way clutch OW1. When the registration sensor S5 detects the leading end of the fed original sheet,
After a predetermined time t1 from the detection, the sheet feeding motor M1 is temporarily stopped (S3 to S5). When the feed motor M1 stops, the leading end of the original sheet is applied to the nip portion of the registration roller pair 21 to form a flexure, the leading end of the original sheet is aligned, and the skew is removed (see FIG. 22A). ). After the stop, the sheet feeding motor M1 is driven to rotate in the reverse direction, the transport motor M2 is driven, and the press-contact solenoid SOL is excited (S6, S7). At this time, the feed roller 18 moves up to a position separated from the document, and the paper feed roller 19 moves to the one-way clutch OW2.
The drive is interrupted by the action of (1), and the registration drive roller 21a of the registration roller pair 21 is rotated in the document feeding direction.

By rotating the motors M1 and M2,
The document D1 is transported from the paper feed path 25 to the transport path 26, and after the lead sensor S6 detects that the leading end of the document D1 has passed, t
After three hours, the feed motor M1 is stopped, and the transport motor M2 is temporarily stopped (S8 to S10) (FIG. 22).
(B)). Then, upon receiving the reading conveyance signal from the image reading apparatus main body 1, the conveyance motor M2 is driven again. The front side (one side) of the document D1 is sub-scanned by the reading unit,
It is read (S11-S12). At this time, the original D1
Is pushed up the tip of the flapper 29 disposed so as to close the sheet discharge path 27 at the tip thereof, and is conveyed onto the sheet discharge tray 16.

When the registration sensor S5 detects that the trailing edge of the document D1 has passed after the document D1 has been sent out, it checks whether or not there is the next document in the sheet tray 15.
When there is an original, the feeding operation of the second original D2 is started as in the case of the first original D1 (S13 to S15). When the second original D2 is fed, the feed roller 18 is driven by the normal rotation of the feed motor M1 as in the case of the previous original, and
The paper feed motor 19 rotates to move the original D2 to the registration roller pair 2
The skew is removed by abutting the nip point 1 (S16 to S19) (see FIG. 22C). Then, after a predetermined time t3 since the feed motor M1 is driven to rotate in the reverse direction and the read sensor S6 detects the leading end of the next document, the drive of the feed motor M1 is stopped, and the transport motor M2 is also stopped.
(S20-S23). Here, the original document D2 is in a state where the leading end position is stopped before the contact glass, and the first original document D1 is nipped by the paper discharge roller pair 24 at the trailing end and stops. 23 (d)).

Then, upon receiving the reading and conveying signal from the image reading apparatus main body 1, the conveying motor M2 is driven again. The surface of the document D2 is sub-scanned and read by the above-described reading means (S24 to S25). During reading of the second document D2, the first document D1 is discharged onto the discharge tray 16 (see FIG. 23E).

The passage of the rear end of the document D2 is detected by the registration sensor S
5 is detected, it is confirmed whether or not the empty sensor S4 detects the presence of the next document.
The feeding operation of the third document D3 is started in the same manner as the first document D2. Thereafter, as long as the empty sensor S4 detects the presence of the original (S14 to S25), the originals D4, D5,.
A similar process is performed for.

In the last document, in step S14, the empty sensor S4 is turned off.
After a time t5 required for the sheet to be discharged to the sheet discharge tray 16 after the discharge sensor S7 detects the trailing end of the last document sheet, the drive of the transport motor M2 is stopped, and the excitation of the pressure contact solenoid SOL is released. Is completed (S26).
To S28).

Next, a duplex mode for reading one side of a document will be described with reference to FIGS.

When the empty sensor S4 detects that a document sheet has been placed on the paper feed tray 15, the first document D1 is driven forward by the paper feed motor M1 similarly to S1-S10 in the single-sided mode. The feed roller 18 and the paper feed roller 19 are rotated to skew the original sheet against the nip point of the registration roller pair 21 to remove skew, and the paper is conveyed by the reverse rotation drive of the paper supply motor M1 and the forward rotation drive of the conveyance motor M2. After the leading edge of the original document D1 is detected by the lead sensor S6, the sheet feeding motor M1 and the transport motor M2 are temporarily stopped, and the leading edge position of the original document D1 is stopped short of the contact glass 2. At this time, the pressure contact solenoid SOL is excited, and the sheet discharge roller pair 24 is pressed (S51 to S60) (see FIG. 24A).

When a reading and conveying signal from the image reading apparatus main body 1 is received, the conveying motor M2 is driven to rotate in the normal direction, so that the surface of the original sheet is sent onto the contact glass 2 and is sub-scanned by the reading means and read. The original D1 that has been read by the contact glass 2 is
(S61 to S62).

The document D1 guided to the paper discharge path 27 receives a flapper 29 arranged so as to close the paper discharge path 27 at its leading end.
Is pushed up to be conveyed onto the discharge tray 16. In this transport state, when a time t11 required for the trailing edge of the document D1 to pass through the position of the flapper 29 after the paper ejection sensor S7 detects the trailing edge of the document D1, the drive of the transport motor M2 is stopped, The trailing end of the document D1 is nipped by the paper discharge roller pair 24 and stopped (S63 to S65) (FIG. 2).
4 (b)).

Thereafter, the transport motor M2 is driven to rotate in the reverse direction (S66 to S67). As a result, the paper ejection drive roller 24
a rotates in the reverse direction, the document D1 is switched back, and the switchback path 28 is moved along the document guide surface of the flapper 29 which has moved to a position where the sheet discharge path 27 is closed as the document sheet passes.
Will be guided. The conveyance motor M2 driven in the reverse direction drives the registration roller pair 21 after the leading edge of the document D1 guided to the switchback path 28 is detected by the registration sensor S5.
Is formed at the nip portion, the skew is removed, and the nip is stopped after a predetermined time t1 has elapsed (S68 to S7).
0) (see FIG. 24 (c)).

Then, the paper feeding motor M1 is driven to rotate in the reverse direction to re-feed the original D1 (S71). Paper feed motor M1
When the registration drive roller 21a rotates in the paper feeding direction by the reverse rotation of the roller, the pressing solenoid S
The excitation of the OL is released, the discharge driven roller 24b is moved downward to be separated from the discharge drive roller 24a, and the transport motor M2 is driven to rotate forward (S72 to S7).
3).

The original D1 is inverted and fed along the paper feed path 25. When the leading end of the original D1 is detected by the read sensor S6, the transport motor M2 stops after a predetermined time t3 and stops the paper feed motor M1. (S74 to S76).
Thereafter, the conveyance motor M2 is driven again by the reading conveyance signal from the image reading apparatus main body 1, and the back surface of the document D1 is sub-scanned and read by the reading means (S77, S7).
8). At this time, the leading end of the document D1 sent to the discharge tray 16 and the rear end of the document D1 to be re-supplied pass each other at a common portion of the discharge path 27 including the discharge roller pair 24 and the switchback path 28. However, the sheet can be conveyed without any trouble because the sheet discharge roller pair 24 is separated (FIG. 25).
(D)).

Thereafter, when the registration sensor S5 detects the trailing end of the document D1, the pressure contact solenoid SOL is excited and the sheet discharging roller pair 24 is pressed, and the sheet discharging sensor S7 detects the trailing end of the document D1. When the time t11 elapses, the drive of the transport motor M2 stops, and the document D1 stops after its trailing end is nipped by the discharge roller pair 24 (S79 to S8).
3) (see FIG. 25 (e)).

Then, in order to discharge the document D1 to the discharge tray 16 in the order of the pages, the transport motor M2 is driven to rotate in the reverse direction, and the leading end of the document D1 is placed in the nip portion of the registration roller pair 21 in the switchback path 28. To skew the sheet, the sheet is inverted and fed along the sheet feeding path 25 by the reverse rotation driving of the sheet feeding motor M1, and the driving of the sheet feeding motor M1 is stopped by the leading sensor S6 detecting the leading end of the document D1 (S84). ~
S90).

Then, the conveying motor M2 is driven forward to release the press-contact solenoid SOL, and the original D1 is conveyed onto the contact glass 2. However, since the original D1 is not scanned, the contact glass 2 is not scanned. Is transported to the paper discharge path 27 without stopping immediately before (S9).
1 to S94).

When the original sensor D5 detects the rear end of the original document D1 in the course of transporting the original document D1 to the paper discharge path 27 (S95), the pressure contact solenoid SOL is excited to press the paper discharge roller pair 24. At the same time, it is checked whether or not there is a document on the document tray 15 (S96).
The feeding operation of the second original D2 is started in the same manner as the first original D1.

In the process of controlling the feeding of the second original D2, as in the case of the preceding original D1, the feed roller 18 and the feeding motor 19 are rotated by the normal rotation of the feeding motor M1 to rotate the original D2.
2 is abutted against the nip point of the registration roller pair 21 to remove skew (S94 to S101) (FIG. 25).
(F)).

Then, the sheet feeding motor M1 is driven to rotate in the reverse direction, and the original D2 is fed along the sheet feeding path 25, and the second original D
During reading of the second document, the first document D1 is discharged to the discharge tray 16 (S102).

Thereafter, the second original D2 is processed in the control steps S58 to S96 in the same manner as the first original D1, and as long as the empty sensor S4 detects the presence of the original, the original D2 is processed. Similar processing is performed for D3, D4,.

Note that the last original is
Since the empty sensor S4 is in the OFF state,
After the time t5 required for the paper to be discharged to the paper discharge tray 16 after the discharge sensor S7 detects the trailing end of the last document, the drive of the transport motor M2 is stopped, and the excitation of the pressure contact solenoid SOL is released. Of the original document (S103-
S105).

As described above, in the present embodiment, the original feed path is configured so that the original fed from the paper feed tray and the original to be switched back and fed back are aligned at the same position and the leading ends thereof are aligned. Therefore, the document feed path is short and simplified, and efficient conveyance is possible.

The branch position between the paper feed path for guiding the original sheets fed from the paper feed tray and the switchback path for guiding the original sheets switched back is set as the matching position of the leading end of the original sheets. The paper feed path and the switchback path upstream of the alignment position can be configured to be substantially straight, and the original sheets can be reliably aligned. Further, since the flexible film member which guides the leading edge of the document to the alignment position is provided at the branch position, the leading edge of the document can be reliably guided to the alignment position, whereby the document is reliably aligned.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an automatic document feeder mounted on an image reading apparatus according to the present invention.

FIG. 2 is an enlarged vertical sectional view of the automatic document feeder shown in FIG.

FIG. 3 is a diagram showing a state when the document conveying path of the automatic document feeder shown in FIG. 1 is opened.

FIG. 4 is a diagram illustrating a state in which a document conveyance path of the automatic document feeder illustrated in FIG. 1 is opened.

FIG. 5 is a drive diagram of the automatic document feeder shown in FIG.

FIG. 6 is a drive diagram of the automatic document feeder shown in FIG.

FIG. 7 is a cross-sectional view illustrating a main part of the automatic document feeder shown in FIG.

FIG. 8 is a flowchart (part 1) of a conveyance control operation in the one-sided mode of the automatic document feeder shown in FIG.

9 is a flowchart (part 2) of a conveyance control operation in the single-sided mode of the automatic document feeder shown in FIG.

FIG. 10 is a flowchart (part 3) of a conveyance control operation in the one-sided mode of the automatic document feeder shown in FIG. 1;

FIG. 11 is a flowchart (part 4) of a conveyance control operation in the one-sided mode of the automatic document feeder shown in FIG. 1;

12 is a flowchart (part 5) of a conveyance control operation in the single-sided mode of the automatic document feeder shown in FIG. 1;

13 is a flowchart (part 6) of a conveyance control operation in the one-sided mode of the automatic document feeder shown in FIG.

FIG. 14 is a flowchart (part 7) of a conveyance control operation in the one-sided mode of the automatic document feeder shown in FIG. 1;

FIG. 15 is a flowchart (part 8) of the conveyance control operation in the one-sided mode of the automatic document feeder shown in FIG. 1;

16 is a flowchart (part 9) of a conveyance control operation in the one-sided mode of the automatic document feeder shown in FIG. 1;

FIG. 17 is a flowchart (part 10) of a conveyance control operation in the one-sided mode of the automatic document feeder shown in FIG. 1;

FIG. 18 is a flowchart (part 11) of a conveyance control operation in the one-sided mode of the automatic document feeder shown in FIG. 1;

19 is a flowchart (part 12) of a conveyance control operation in the one-sided mode of the automatic document feeder shown in FIG. 1;

FIG. 20 is a flowchart (part 13) of a conveyance control operation in the one-sided mode of the automatic document feeder shown in FIG. 1;

FIG. 21 is a flowchart (part 14) of a conveyance control operation in the one-sided mode of the automatic document feeder shown in FIG. 1;

FIG. 22 schematically illustrates a state (part 1) of document conveyance in the one-sided mode of the automatic document feeder illustrated in FIG.

FIG. 23 schematically shows a state (part 2) of document conveyance in the one-sided mode of the automatic document feeder shown in FIG.

FIG. 24 schematically shows a state (part 1) of document transport in the duplex mode of the automatic document feeder shown in FIG.

FIG. 25 schematically illustrates a state (part 2) of document conveyance in the duplex mode of the automatic document feeder illustrated in FIG. 1;

FIG. 26 is a cross-sectional view showing a conventional technique of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 Automatic document feeder 10 a Outer cover 11 Feeder 12 Transporter 13 Discharger 14 Switchback 15 Document tray 16 Discharge tray 18 Feeding roller 19 Feeder roller 20 Separation pad 21 Register roller pair 24 Discharge roller pair 25 Feeder Paper path 26 Transport path 27 Paper discharge path 28 Switchback path S5 Registration sensor S5

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Osamu Kanza, Inventor Osamu Kobayashi, 430-1, Kobayashi, Masuho-machi, Minami-Koma-gun, Yamanashi Prefecture (72) Motoaki Nakayama 430-1, Kobayashi, Masuho-cho, Minami-Koma-gun, Yamanashi (72) Inventor Masataka Hamada 430-1, Kobayashi, Masuho-machi, Minamikoma-gun, Yamanashi Prefecture Niska Corporation F-term (reference) 2H076 AA58 BA24 BA35 BA36 BA42 BA58 BB02 BB05 3F100 AA03 BA13 CA12 CA15 EA17 3F102 AA05 AB01 BA02 BA11 BB02 CA01 CB01 DA08 EA03 5C072 AA01 BA01 EA05 NA01 NA06 NA08 RA04 RA05 WA02

Claims (6)

[Claims] 1. An image on both sides of a document sheet to be conveyed,
An automatic document feeder for sequentially reading one side at a time using a reading device arranged on one side of the document sheet conveyance path, wherein the document sheet is provided upstream of the document path for reading the document sheet and supplied. Aligning means for aligning the leading end of the original sheet with respect to the transport path; the aligning means receives and aligns the original sheet from an original sheet supply path to read one surface, and aligns the reading apparatus. In order to read the other side of the original sheet which has been turned over via
An automatic document feeder having a function of receiving the front and back reversed sheets from a reversed document sheet supply path and aligning them. 2. The automatic original according to claim 1, wherein said aligning means is a pair of registration rollers in which rotation for conveying said original sheet and rotation stop for aligning said original sheet are controlled. Feeder. 3. The automatic document feeder according to claim 2, wherein the alignment of the document sheet is performed by abutting the document sheet against a nip point of the pair of registration rollers. 4. The document sheet supply path and the reverse document sheet supply path are configured to merge at an upstream thereof toward a nip point of the pair of registration rollers.
Or the automatic document feeder according to 3. 5. The document sheet supply path according to claim 3, wherein a guide member for guiding a leading end of the document sheet to a nip point of the pair of registration rollers is provided between the document sheet supply path and the inverted document sheet supply path. Automatic document feeder. 6. The conveyance of the document sheet is performed by using a first drive motor and a second drive motor as drive sources.
The drive motor drives the paper feed roller that conveys the document sheet in the document sheet supply path by the forward rotation, and drives the registration roller by the reverse rotation, and the second drive motor The automatic document feeder according to claim 2, wherein a transport roller that causes the original sheet to pass through the reading device and a reversing roller that transports the reverse document sheet in the reverse document sheet supply path are driven to rotate forward and reverse.