JP2609481B2 - How to feed a sheet original - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document feeder provided in, for example, a copying machine or the like, which continuously feeds a plurality of sheet-shaped documents onto a document reading surface for reading exposure. In particular, the present invention relates to a sheet-form original feeding method which is particularly advantageously performed.

2. Description of the Related Art Conventionally, copiers have tended to be equipped with a document feeder that automatically and sequentially feeds a plurality of sheet-shaped documents onto a document reading surface for the convenience of an operator. The document to be copied is placed on a placing member, and is sequentially fed, for example, from the bottom in the stacking direction. On the original reading surface, an original image is sequentially fed toward the inside of the machine by a transport belt, read and exposed by, for example, an optical reading unit, and cooperated with a copying machine to perform double-sided or single-sided copying. And so on.

FIG. 7 is a cross-sectional view showing a simplified configuration of a conventional document feeder 201. The document d to be copied is placed on the placing member 20.
6 stacked on top. Feeding direction 207 of mounting member 206
On the downstream side, a paper feeding unit 210 for sequentially feeding the originals d one by one is provided. The paper feeding unit 210 includes, for example, a mounting member.
The suction conveyance unit 211 includes a suction conveyance unit 211 disposed below the 206 and an exhaust duct 212 disposed above the mounting member 206.

The suction conveyance means 211 includes an endless belt 215 having a large number of openings wound between two drive rollers 213 and 214 having an axis in a direction perpendicular to the paper feeding direction 207. The drive rollers 213 and 214 are driven by a motor m1. On the inner side of the belt 215, an intake duct 216 is arranged, and by driving an intake fan (not shown),
Attraction force acts from the intake duct 216 via a belt 215, and the lowest document of the stacked documents d is
Sucked in 215. Therefore, the drive rollers 213 and 214
Is driven clockwise, the lowermost document d in the stacking direction is sequentially fed in the feeding direction 207.

From the nozzle of the exhaust duct 212, an air flow is jetted toward the downstream end in the sheet feeding direction of the document d on the lower side in the stacking direction.
As a result, the downstream end is separated one by one, and the sheet feeding by the suction conveyance unit 211 is surely performed one by one. The document d fed by the paper feeding unit 210 is transported to the transport path 204 and the reversing unit 218.

The reversing means 218 includes transport paths 222 and 229, a pair of transport rollers 220, 221, and 230, a direction switching claw 228, and motors m2 and m3. In the vicinity of the direction switching claw 228, the transport path 240 branches into a first transport path 222 extending in a clockwise direction and a second transport path 229 extending in a counterclockwise direction.

Transport rollers 220 and 221 are provided on the first transport path 222, and can be driven to rotate forward and reverse by a driving force from a motor m2. Further, a transport roller 230 is provided in the second transport path 229, and is driven by a driving force from a motor m3. The direction switching claw 228 is driven by, for example, a solenoid. For example, if the solenoid is demagnetized, the transfer path 240
The path for transporting the document d from the first transport path 222 to the first transport path 222 is opened. On the other hand, when the solenoid is excited,
A path for transporting the document d from the first transport path 222 to the second transport path 229 is opened.

The first transport path 222 and the second transport path 229 join near the upstream end in the feeding direction 223 with respect to the transparent plate 205 constituting the document reading surface. Therefore, the document d conveyed by the reversing means 218 based on each set copy mode is conveyed onto the transparent plate 205 along the feeding direction 223.

On the upper side of the transparent plate 205, two rollers 224a and 224b having an axis parallel to the width direction of the document d to be fed are arranged along the feeding direction 223, and a plurality of endless belts 226 are wound around the rollers 224a and 224b. It is hung. The roller 224a is driven by a motor m4. A plurality of press rollers 225a to 225d are provided on the inner surface side of the belt with respect to the lower tension portion of the belt 226 in the feeding direction.
Arranged along 223. This press roller 225a ~ 225d
Presses the belt 226 toward the transparent plate 205,
While avoiding the slack in tension of 226, the belt 226
Of the document d fed between the document and the transparent plate 205 is prevented.

The document d conveyed on the transparent plate 205 by the belt 226 is conveyed to a reading position on the transparent plate 205. The document d conveyed to the reading position has its document image presented to the inside of the copying machine, and the document image is optically scanned by an optical system as an optical reading means provided inside the copying machine. Then, the exposure operation for reading the original image is performed.

While the previously fed original is being scanned and exposed,
The subsequent document is preliminarily fed. The following original is waiting just before the transparent plate 205.

When the reading and exposure operation of the document image is completed, the belt 226 is driven to rotate again, and the document d is conveyed to the conveyance path 236, further conveyed by the conveyance rollers 234 and 235, and then the document d stacked on the placing member 206. It is stored again at the top in the stacking direction.

Problems to be Solved by the Invention In the above-described document feeder 201, the transport roller 230 and the roller 224a are driven by separate motors m3 and m4, respectively. Further, since the conveyance speed of the conveyance roller 230 is lower than the conveyance speed of the belt 226, even if the preliminary feeding of the document d is performed, the document interval on the transparent plate 205 does not become short. For this reason, it has not been possible to reduce the time spent for transporting a plurality of sheet-shaped documents onto the document reading surface.

SUMMARY OF THE INVENTION It is an object of the present invention to reduce a plurality of sheet-shaped originals by making the conveyance interval between the preceding sheet-shaped original and the succeeding sheet-shaped original sufficiently close by a simple control method, and further realizing sufficient preliminary feeding. An object of the present invention is to provide a sheet-form document feeding method that can significantly reduce the time spent for transporting a document on a catch-up surface.

Means for Solving the Problems The present invention is directed to reversing the feeding direction after transporting a plurality of sheet-form documents fed from a placing member to one of the branched transport routes, and the other of the branched transport routes. , A sheet-like document feeding method that is sequentially and sequentially conveyed onto a post-document reading surface facing the optical reading means, wherein the upstream end of the preceding first sheet-shaped document in the feeding direction after the reversal is the conveyance path When the first sheet-shaped document is passed, the conveyance of the first sheet-shaped document is stopped, the feeding direction of the succeeding second sheet-shaped document is reversed, and the succeeding third sheet-shaped document is further moved to near the branch position. When the interval between the downstream end of the second sheet-shaped original in the feeding direction after the reversal and the upstream end of the stopped first sheet-shaped original in the feeding direction becomes a predetermined length, the first and the second are set. It is specially designed to feed sheet documents at a constant speed. This is a method for feeding a sheet-shaped original.

According to the present invention, the sheet-shaped document fed from the mounting member is first conveyed to one of the branched transport paths, the feeding direction is reversed, and the document is fed through the other branched transport path. It is transported onto the reading surface. The above-described conveying operation is sequentially performed over a plurality of sheet-shaped originals, and in this way, the succeeding sheet-shaped original is conveyed continuously to the preceding sheet-shaped original.

In the present invention, when the upstream end of the preceding first sheet-shaped document after reversing in the feeding direction passes the branch position of the conveyance path, the conveyance of the first sheet-shaped document is stopped, and the subsequent second sheet is stopped. The feeding direction of the original is reversed. As a result, it is possible to make the space between the first sheet-shaped document and the second sheet-shaped document sufficiently close. Further, during the reversal of the feeding direction of the second sheet-shaped document, the subsequent third sheet-shaped document is transported to near the branch position of the transport path.

Thereafter, when the interval between the downstream end in the feeding direction of the inverted second sheet document and the upstream end in the feeding direction of the stopped first sheet document becomes a predetermined length, the first and second sheets are set. The original is fed at a constant speed. The predetermined length is set to the second length when the first sheet-shaped document stops on the document reading surface.
The length is selected such that the upstream end of the sheet-shaped document after the reversal in the feeding direction stops at a point where the first sheet-shaped document has stopped (a point where the first sheet-shaped document has stopped).

Therefore, the first and second sheet-shaped originals can be conveyed onto the original reading surface in a state where they are sufficiently close to each other. Widening of the interval between the originals is prevented.

Also, while the second sheet-shaped original is stopped, that is, while the first sheet-shaped original is being read and exposed, the third sheet-shaped original is read.
The feeding direction of the sheet document is reversed, and the sheet document following the third sheet document is transported to the branch position of the transport path. Hereinafter, such an operation is continuously performed.

Therefore, it is possible to carry out preliminary feeding in which the succeeding sheet-shaped document is brought close enough to the preceding sheet-shaped document and is on standby, and as a result, the document reading surface of the succeeding sheet-shaped document after the completion of reading and exposure of the preceding sheet-shaped document It is possible to remarkably reduce the time required to carry the paper upward, thereby shortening the copying time.

FIG. 1 is a sectional view showing a simplified configuration of a document feeder 1 according to an embodiment of the present invention, and FIG. 2 is a transfer electrostatic copying machine equipped with the document feeder 1. 2 is a sectional view showing a simplified configuration of FIG.

A transparent plate 5 made of a material such as hard glass is provided on the upper body side surface 3 of the copying machine body 2. The transparent plate 5 forms a document reading surface. The document feeder 1 is mounted above the transparent plate 5 and is attached, for example, on the upper side surface 3 of the machine body so as to be angularly displaceable with respect to the rotation shaft 4. When the document is not fed by the document feeder 1 (for example,
When the original is a book or the like), the apparatus 1 is angularly displaced around the rotation axis 4, and the original is placed on the transparent plate 5 with the original image directed toward the inside of the machine, and is pressed and fixed. The copying operation is performed in the state in which the copying is performed.

Generally, as shown in FIGS. 1 and 2, the document feeder 1 is arranged so as to cover a transparent plate 5 and is a sheet-shaped document stacked and placed on a placing member 6. D is automatically fed sequentially to the reading position 5a on the transparent plate 5, and the original image is presented. The presented document image is optically scanned by an optical reading means provided in the copying machine 2, and the reading operation of the document image is performed. The original D from which the original image has been read is
It is stored again in the mounting member 6. The transfer is performed by the placing member 6.
Are performed sequentially on the originals D stacked on each other, and are circulated between the originals according to the required number of copies, thus performing one-sided copying or double-sided copying on the recording paper P.

Hereinafter, the configuration of the document feeder 1 will be described with reference to FIG.

The originals D to be copied are stacked and mounted on the mounting member 6. The placement member 6 is provided with a pair of alignment plates 8 facing each other in the width direction perpendicular to the paper feeding direction 7. The alignment plate 8
Move toward and away from each other according to the width dimension of the documents D to be stacked along the directions facing each other to align both ends of the documents D in the width direction. That is, originals D to be stacked
The center position in the width direction is constant irrespective of the size in the width direction. A rear end alignment plate 9 for aligning the upstream end of the stacked originals D in the feeding direction is disposed at the upstream end of the originals D stacked in the feed member 7 in the feeding direction 7. Is done.

On the downstream side of the placing member 6 in the sheet feeding direction, a sheet feeding means 10 for sequentially feeding the documents D one by one is provided. The paper feeding unit 10 includes, for example, a suction conveyance unit 11 disposed below the mounting member 6 and an exhaust duct 12 disposed above the mounting member 6. The suction conveyance means 11 includes two drive rollers 1 having an axis in a direction perpendicular to the paper feeding direction 7.
An endless belt 15 having a large number of openings is wound between 3,14. The drive rollers 13, 14 are driven by a motor M1. On the inner side of the belt 15, an intake duct 16 is arranged, and by driving an intake fan (not shown), an attraction force acts from the intake duct 16 via the belt 15, and the intake duct 16 is stacked. The lowermost original of the original D is sucked by the belt 15. Accordingly, by driving the driving rollers 13 and 14 clockwise (see FIG. 1), the lowermost originals D in the stacking direction are sequentially moved in the feeding direction 7.
Paper is fed toward.

An air flow is jetted from the nozzle of the exhaust duct 12 toward the downstream end in the paper feeding direction of the document D on the lower side in the stacking direction. As a result, the downstream end is separated one by one, so that the suction and conveyance means 11 can surely feed one sheet at a time. In this way, the documents D to be stacked can be sequentially fed from the lower side in the stacking direction by the feeding means 10. Incidentally, the paper feeding means 10
Is not limited.

The document D fed by the paper feed unit 10 is transported to the transport path 40 and the reversing unit 18 via the transport roller 17. Further, a first transport detector S1 including, for example, a light emitting element S1a and a light receiving element S1b is provided downstream of the placing member 6 in the sheet feeding direction. The first conveyance detector S1 detects the reliable feeding of the originals D one by one.

In FIG. 1, a reversing means 18 includes a substantially cylindrical support cylinder 19.
Formed on the outer surface of the A transport path 40 having the transport rollers 17 includes a first transport path 22 extending in a clockwise direction (see FIG. 1) on the outer surface of the support tube 19 and a second transport path 22 extending in a counterclockwise direction. It branches to two transport paths 29. On the first transport path 22, transport rollers 20, 21 for pressing and transporting the document D along the outer surface of the support cylinder 19 are provided, and are rotated forward and reverse by a driving force from a motor M2 via a clutch CLT3 (not shown). It can be driven.

Also, for example, a light emitting element
A second transport detector S2 including S2a and a light receiving element S2b is provided. The second transport detector S2 controls the first transport path 22
The transport state of the document D transported by
The rotation timing and rotation direction of 20, 21 are controlled.

The second transport path 29 is provided with a transport roller 30 for pressing and transporting the document D along the outer surface of the support cylinder 19. The drive shaft of the transport roller 30 is connected to a motor via a clutch CLT1.
Connected to M3. Therefore, by controlling the connection / disconnection of the clutch CLT1, the rotation / stop of the transport roller 30 in one direction is controlled. Further, the second transport path 29
A third transport detector S3 including, for example, a light emitting element S3a and a light receiving element S3b is provided above. The third transport detector S3
Thereby, the transport state of the document D transported on the second transport path 29 is detected, and the rotation timing of the transport roller 30 and the like are controlled.

At a branch point between the first transport path 22 and the second transport path 29, a direction changing claw 28 driven by a solenoid SOL1 is provided.
Is arranged. For example, when the solenoid SOL1 is demagnetized, as shown by the solid line in FIG.
A passage for transporting the document toward the transport path 22 is opened. On the other hand, when the solenoid SOL1 is excited, the direction changing claw 28 is angularly displaced to the position shown by the dotted line, and the passage for conveying the document from the first conveyance path 22 to the second conveyance path 29 is opened. The switching of the solenoid SOL1 is controlled based on the detection result of the second transport detector S2, for example.

The side of the first transport path 22 and the second transport path 29 opposite to the direction changing claw 28 joins near the upstream end of the transparent plate 5 in the feeding direction 23. Therefore, the document D transported by the reversing means 18 based on each copy mode set as described later is transported onto the transparent plate 5 along the feeding direction 23.

Above the transparent plate 5, two rollers 24a and 24b having an axis parallel to the width direction of the original D to be fed are arranged along the feeding direction 23, and a plurality of endless belts 26 are provided. Is wrapped around. The drive shaft of the roller 24 is a clutch CL
The motor M3 is connected via T2. Therefore, by controlling the connection / disconnection of the clutch CLT2, the belt 26 is controlled.
Is switched. Under tension part of the belt 26
A plurality of (four in this embodiment) press rollers 25a to 25d are provided on the inner surface side of the belt with respect to 26a.
Are arranged in this order. The press rollers 25a-2
5d presses the belt 26 toward the transparent plate 5, and
This prevents the tension of the document 26 from being loosened and prevents the document D fed between the belt 26 and the transparent plate 5 from floating.

Also, due to the step between the position where the belt 26 is stretched on the roller 24a and the device for stretching the belt 26 on the press roller 25a on the most upstream side in the feeding direction, the vicinity of the transparent plate 5 near the upstream in the feeding direction 23 A gap 27 is formed. That is, the press roller
On the upstream side in the feeding direction with respect to 25a, the belt 26 is inclined with a fixed angle θ with respect to the transparent plate 5 with the press roller 25a as a base point.

The gap 27 is the first transport path in the reversing means 18 described above.
22 and the second transport path 29. Therefore, in the gap 27, even when the belt 26 is stopped,
The document D can enter and be conveyed by the conveying force of each of the conveying rollers 20, 21, 30 in the reversing means 18.

The document D conveyed on the transparent plate 5 by the belt 26 is conveyed to a reading position 5a on the transparent plate 5.
The reading position 5a corresponds to a position where the downstream end of the fed document D in the feeding direction abuts on a contact piece 32 protruding near the downstream end of the transparent plate 5 in the feeding direction 23. . In this manner, the original D conveyed to the reading position 5a has its original image presented to the inside of the machine, and the optical system 31 serving as an optical reading means provided inside the copying machine 2 for the original image. Optical scanning, and the reading and exposure operation of the original image is performed.

While the previously fed original is read and exposed, the subsequent original is preliminarily fed. Subsequent manuscript
In the state where the sheet has entered 27, the preliminary sheet feeding can be completed and the apparatus can be on standby. The distance from the vicinity of the press roller 25a, where the downstream end of the pre-fed document in the feeding direction reaches, to the contact piece 32 is a size that is sufficiently acceptable regardless of the size of the fed document. The original is appropriately selected so that the preceding original does not collide with the preliminarily fed original.

When the reading exposure operation of the original image is completed, the contact piece 32 is driven to be angularly displaced by the control of the solenoid SOL2, and the reading position is changed.
The passage from 5a to the transport path 36 is opened. at the same time,
The belt 26 is driven to rotate again, and the document D is transported along the transport path 36 by the transport rollers 33 to 35, and then is re-stored at the highest position in the stacking direction of the document D stacked on the placing member 6.

On the transport path 36, for example, a discharge detector S4 including a light emitting element S4a and a light receiving element S4b is arranged. The document D conveyed on the conveyance path 36 by the discharge detector S4
Is detected, and the drive timing of the solenoid SOL2 is controlled. In the vicinity of the placing member 6, a one-circle detector S5 for detecting one-circle conveyance over the stacked originals D is provided. The detector S5 includes, for example, an operating member that comes into contact with the top of the stacked originals D. The original D is placed between the operating member and the mounting member 6 according to the feeding of the originals D. Is detected, for example, optically, it can be determined that all the originals D have been fed and circulated once.

As described above, the reading exposure operation is performed by the optical system 31 on the document image presented to the reading position 5a. Optical system
In 31, a first moving body 43 including a light source 41 such as a halogen lamp and a reflecting mirror 42 is arranged in a horizontal direction with respect to the reading position 5 a.
The document reciprocates along 44 and irradiates the presented document with light, and the reflected light is reflected by the reflecting mirrors 46 and 47 of the second moving body 45 and the zoom lens 4.
An image is formed on a photoreceptor 51 of a straight cylindrical shape which is driven to rotate in the direction of arrow 50 through 8 and a reflecting mirror 49. The second moving body 45
Also, it is driven to travel in the same direction as the first moving body 43 at half the scanning speed, and the optical path length of the reflected light is kept constant.

The surface of the photoconductor 51 is charged in advance by a charging corona discharger 52, and an electrostatic latent image corresponding to a document image is formed on the photoconductor 51 by the image formation. The electrostatic latent image is visualized as a toner image by a developing device 53 and is transferred to one surface of the recording paper P by a corona discharger 54 for transfer. The recording paper P is stored in a paper feed cassette 55 in advance, is transported along a transport path 57 having a pair of registration rollers 56, and is guided to a transfer area 58 where transfer is performed. Power transmission means is connected to the rotation shaft of the registration roller 56 via a clutch CLT4 (not shown). The clutch CL
The connection / interruption control of T4 is performed by the original D in the original feeding device 1.
The photoconductor is controlled by the
The transfer timing of the recording paper P by the registration roller 56 can be matched with the toner image on the toner image 51. The recording paper P on which the toner image has been transferred by the transfer corona discharger 54 is
The sheet is guided from the conveying means 59 to the fixing device 60 to be fixed.

The recording paper P after fixing is reversed in the transport direction of the recording paper P by the recording paper reversing means 61, and is temporarily stored in the intermediate tray 63 via the transport path 62. The recording paper P on the intermediate tray 63 is again transferred to the transfer area by the conveying means 64 and the registration rollers 56.
The toner image is transferred to the other surface of the recording paper P by being guided to 58. The recording paper P on which the transfer has been completed is conveyed to the conveying means 59 and the fixing device.
The sheet is discharged to a discharge tray 66 outside the apparatus via the transfer path 60 and the transfer path 65. In this way, the original images of the originals D corresponding to the front and back sides of the corresponding recording paper P are copied. Note that when only copying is performed on one side, the recording paper P copied on one side is not discharged to the intermediate tray 63, but is discharged to the discharge tray 66.
Is discharged to From the paper feed cassettes 55, 67 to 69, for example, recording papers P having mutually different dimensions are selectively conveyed to the transfer area 58.

FIG. 3 is a block diagram showing an electrical configuration of the document feeder 1 and the copying machine 2. The motors M1, M2, M3... For driving the plurality of rollers and the like are provided to the motor drive circuit 110 by a clutch CL for controlling the timing of driving the transport roller 30 and the belt 26.
T1, CLT2, CLT3,... Are solenoids SOL1, SOL2,.
Are connected to the solenoid drive circuit 112, respectively. Control elements such as the drive circuits 110 to 112 and the DC power supply 114 used for document conveyance control, recording paper conveyance control, and control of a copying process are connected to an interface circuit (I / O) 113. This interface circuit 113 includes a document D
, And various detectors S1, S2,... For detecting the conveyance of the recording paper P, and a microcomputer (CPU) 120 are further connected. The signal from the detector is supplied to the microcomputer 120, and the microcomputer 120 performs an arithmetic processing corresponding to the signal, and a drive control signal is supplied to each of the drive circuits 110 to 112 via the interface circuit 113.

A ROM (Read Only Memory) 121 and a RAM (Random Access Memory) 122 are connected to the microcomputer 120. The microcomputer 120 has a ROM 121
The control operation is performed using the storage area of the RAM 122 as a work area based on the control program recorded in the.

The interface circuit 113 is connected to the optical system 31 via a drive circuit 115, and powers the light source 41, and provides a display control signal to each display unit 118 of the operation panel 116 via the display drive circuit 117. It is connected to an operation key 119.

Hereinafter, the document D in the document feeding apparatus 1 in each copy mode is described.
Will be described.

FIG. 4A shows the state of conveyance of the one-sided document D. For convenience, FIG. 4 (I) shows the mounting member 6,
The positions of the transparent plate 5 and the reversing means 18 are shown in a simplified manner. The single-sided original D to be copied is stacked on the placing member 6 with the original image facing upward. When the direction changing claw 28 is fixedly set as shown by the solid line in FIG. 1, the document D fed from the bottom in the stacking direction is
It is transported to the first transport path 22 of the reversing means 18. The document D that has passed through the first transport path 22 is transported to the reading position 5a via a gap 27 formed on the transparent plate 5 on the upstream side in the feeding direction. In this way, the front and back surfaces on the placing member 6 are reversed by passing through the reversing means 18, and the document D is brought to the reading position 5a, and the document image is presented.

After the presented original image is read and exposed by the optical system 31, the belt 26 is driven again, and the conveyance path 36
The originals D stacked on the placing member 6 via the sheet are re-stored at the highest position in the stacking direction. Thus, the original image of the one-sided original conveyed to the reading position 5a is read, and one-sided copying and two-sided copying on the recording paper P are realized in cooperation with the copying machine 2.

When sequentially feeding a plurality of originals to the reading position 5a, the original following the original to be fed in advance is preliminarily fed, and sufficient for the preceding original being read and exposed. It is necessary to wait at a close position. Since the gap 27 is formed on the transparent plate 5 continuously from the first transport path 22, the subsequent document is reserved until the downstream end in the feeding direction reaches the vicinity of the press roller 25 a in the gap 27. Paper can be fed, and the user can wait sufficiently close to the preceding document.

FIG. 4B shows the state of conveyance of the double-sided document D. The double-sided document D having a document image to be copied on both front and back surfaces is stacked on the mounting member 6 so that the number of pages is aligned from the upper side in the stacking direction to the lower side. You. The document D fed from the bottom in the stacking direction is conveyed to the reversing means 18. The direction changing claw 28 is first set as shown by a solid line in FIG. 1, and as a result, the conveyed document D is conveyed toward the first conveyance path 22 and the gap 27.

Feeding direction 7 of document D transported to first transport path 22
When the downstream end has passed through the direction changing claw 28, for example, when the second conveyance detector S2 detects that the downstream end has passed, the rotation direction of the conveyance rollers 20, 21 on the first conveyance path 22 is driven to reversely rotate,
Further, the direction changing claw 28 is switched to the position shown by the dotted line in FIG. Therefore, the document D is reversed in the feeding direction, is conveyed from the first conveyance path 22 to the second conveyance path 29, and is conveyed again through the gap 27 to the reading position 5a on the transparent plate 5.

In this manner, at the reading position 5a, the lower surface is presented with respect to the front and back surfaces when being placed on the placing member 6.
Accordingly, the lower surface is read and exposed, and thereafter,
The originals D stacked on the placing member 6 are again stored at the highest position in the stacking direction of the originals D stacked on the placing member 6 via the transport path 36. With respect to the originals D stacked on the placing member 6, the lower surface of each original is read and exposed by circulating the transport operation once, and the lower surface of the intermediate tray 63 in the copying machine 2 is provided. Are stacked and stored.

Subsequently, the transport operation shown in FIG. 4 (2) is executed again on the originals D stored and stacked again. As a result, an unread upper surface is presented at the reading position 5a. The original image on the upper surface is read and exposed, and is copied to the other unprinted surface of the recording paper P fed from the bottom in the stacking direction of the intermediate tray 63, and thus the recording paper on which double-sided copying is completed P is completed sequentially. The document D whose upper surface has been read and exposed is again turned upside down via the transport path 36, and is again stored at the highest position in the stacking direction of the documents stacked on the placing member 6. In this way, the document D that has been subjected to two circulations returns to the original state before placing before copying.

Even when the two-sided document D is conveyed, preliminary feeding is performed to shorten the copying time as described above, and the next document is brought close to the preceding document being read and exposed, and the next document is on standby. Need to be done. Since a gap 27 that is continuous with the first transport path 22 and the second transport path 29 is provided on the transparent plate 5, the downstream end of the document D that has passed through the second transport path 29 in the feeding direction 23 is above the gap 27. The sheet can be fed until it reaches the vicinity of the press roller 25a, and the preliminary sheet feeding sufficiently close to the preceding document can be realized.

Further, according to this embodiment, the preliminary feeding of the subsequent original
The process starts immediately after the preceding document is conveyed from the first conveyance path 22 to the second conveyance path 29 after the reversal. By this early start, the succeeding document can be conveyed sufficiently close to the preceding document, and the preliminary feeding can be surely completed before the end of the reading exposure at the reading position 5a of the preceding document.

FIG. 5 is a timing chart for explaining the feeding operation in this embodiment, and FIG. 6 is a diagram for intermittently explaining the feeding operation of the document D. Hereinafter, an example of the document feeding operation in the present embodiment will be described with reference to FIGS. In FIG. 6, four double-sided originals D to be copied are assumed, and the suffixes 1 to 4 attached to the reference numeral D correspond to the feeding side from the placing member 6.

The two-sided originals D1 to D4 to be copied are placed on the placing member 6 with the page order aligned, and as shown in FIG.
When the print switch PSW is operated at t1 (see FIG. 5 (1)), the copying operation is started and the feeding of the document D is started. As shown in FIGS. 5 (2) to 5 (4), the motors M1 to M1 are operated in accordance with the operation of the print switch PSW.
Drive 3 starts. The motor M1 is driven intermittently to make the paper feeding unit 10 function, and feeds the document D1 at the lowest position in the stacking direction on the placing member 6. Further, the motors M2 and M3 continuously drive until the copying operation stops, and the clutches CLT1, CLT2,
The functions of the transport roller 30 and the belt 26 and the transport rollers 20 and 21 are switched by the connection / disconnection control of the CLT 3.

At time t2, the first transport detector S1 switches to the ON state,
The detection of the downstream end of the fed document D1 in the feeding direction 7 starts. With the switching of the first transport detector S1, the clutch CL
By connecting T3, the transport rollers 20 and 21 are driven to rotate forward to function so as to rotate the document D1 clockwise with respect to the first transport path 22 in the clockwise direction.

The direction changing claw 28 demagnetizes the solenoid SOL1,
This is set at the position shown by the solid line in FIG. 1, and the path from the transport path 40 to the first transport path 22 is open. Therefore, the document D1 is conveyed to the first conveyance path 22, and at time t3, the second conveyance detector S2 is turned on, and the downstream end of the document D1 in the sheet feeding direction 7 starts to be detected. Sixth
FIG. 2B shows a state immediately after time t3 when the document D1 is transported to the first transport path 22.

As shown in FIG. 6 (2), at time t14 when the upstream end of the document D1 in the transport direction passes through the first transport detector S1, the first transport detector S1 is turned off. From this time t14, the motor M1 is driven to start conveying the document D2, and the time t1 at which the downstream end of the document D2 in the conveyance direction is detected by the first conveyance detector S1.
At 5, the motor M1 is stopped. That is, the motor M1 is driven only for the period T2. As a result, the document D2 stops the direction changing claw 28 in the vicinity.

Also, at time t4, the second transport detector S2 is similarly switched off. That is, the upstream end of the document D1 in the paper feeding direction 7 passes through the second conveyance detector S2. At this time t4, the solenoid SOL1 is excited. Therefore, the turning claw 28 is
The position is switched to the position indicated by the dotted line in FIG.
The path that faces the second transport path 29 from is opened. Further, at time t4, the clutches CLT1 and CLT2 are connected, and the motor M3
, And the transport roller 30 and the belt 26 are driven.

Subsequently, immediately after time t4, the clutch CLT3 is connected, and the transport rollers 20, 21 are driven to rotate in the reverse direction to reverse the feeding direction of the document D1. The document D1 whose feeding direction is reversed is transferred to the first transport path 22.
To the second transport path 29. Due to the reversal of the feeding direction described above, the second conveyance detector S2 is switched on again by the downstream end of the reversing feeding direction 23, and is switched off at time t6 with the conveyance. At time t6, the solenoid SOL1 is demagnetized.

In the present embodiment, the downstream end of the document D1 in the feeding direction 23 after the reversal of the feeding direction in the first conveying path 22 passes through the direction changing claw 28, and after a lapse of a predetermined period (time t8), the clutch CLT1 , CLT2 is cut, and the document D1 is stopped while being held between the transport rollers 30, and the subsequent document D2 is moved to the position shown in FIG.
As shown in (1), the paper is preliminarily fed so as to start the conveyance to the first conveyance path 22. Therefore, the motor M1 that starts feeding the document D2 starts driving at time t7. In order to transport the subsequent document D2 to the first transport path 22, the transport roller 2 is moved from the time t7 to a period T3 (T3 = T1−T2).
0 and 21 are driven to rotate forward again, and conveyance of the document D2 to the first conveyance path 22 is started. Accordingly, the second conveyance detector S2 is switched to the ON state, and starts detecting the downstream end of the document D2 in the paper feeding direction 7.

According to the size of the document D2 to be transported, the first transport detector S1
Is turned off, and at the same time, the motor M1 is driven for the period T2 in order to convey the document D3. Subsequently, at time t9, the second transport detector S2 is also switched to the off state. That is, the upstream end of the document D2 in the sheet feeding direction passes through the second conveyance detector S2.
At time t9, the clutch CLT3 is disengaged and the document D2
Is temporarily stopped, and the solenoid SOL1 is excited to open the passage from the first transport path 22 to the second transport path 29 as described above. Then, immediately after time t9, the clutch CLT3 is engaged, and the transport rollers 20, 21 are driven to rotate in the reverse direction, thereby inverting the feeding direction of the document D2. Due to the reversal of the feeding direction of the document D2, the second transport detector S2 is again switched to the ion state by the downstream end of the feeding direction 23 after the reversal (time t10).

At time t11 after a predetermined period elapses from time t10, that is, at time t11 when the interval between the upstream end in the feeding direction 23 of the first original D1 to be stopped and the downstream end in the feeding direction 23 of the original D2 has a predetermined length. (See FIG. 6 (4)), the clutches CLT1 and CLT2 are connected, the rotational driving force of the motor M3 is transmitted, and the transport roller 30 and the belt 26 are rotationally driven, and
D1 is transported to the reading position 5a. From time t11, clutches CLT1 and CLT2 are disengaged at time t12, for example, after a predetermined number of pulses are measured by a rotary encoder or the like. Thus, the conveyance of the document D1 to the reading position 5a is completed.

Here, the transport speed of the original D1 and the transport speed of the original D2 are selected to be equal, and the upstream end of the original D1 in the feeding direction 23 and the original D2
The distance from the downstream end of the feeding direction 23 is always kept constant. This interval is selected to be such a length that when the document D1 is transported to the reading position 5a, the upstream end of the document D2 in the feeding direction 23 is sandwiched between the transport rollers 30 as in the case of the document D1. It is.

FIG. 6 (5) shows a state at the time when the conveyance of the document D1 to the reading position 5a is completed, and the subsequent document D2 is a part of the downstream side in the feeding direction 23 by the above-described preliminary sheet feeding. Is held in a state of being sandwiched between the transparent plate 5 and the belt 26, and a reversing operation of the feeding direction by the reversing means 18 is performed on the succeeding document D3.

At the same time when the document D1 is conveyed to the reading position 5a, the optical system 31
Optical scanning in the direction of arrow 44 starts (see FIG. 1). While the reading exposure operation on the document D1 is being performed, the reversing operation of the subsequent document D3 is performed. FIG. 6 (6) shows a state immediately before time t13, and the original D
The reading exposure operation 1 is completed, the reversing operation of the original D3 in the feeding direction is completed, and the conveyance of the original D4 to the vicinity of the direction changing claw 28 is also completed.

At time t13, the clutches CLT1 and CLT2 are connected, the document D1 is transported to the transport path 36, the document D2 is transported to the reading position 5a, and the document D3 is moved to the upstream end of the document D2 in the feeding direction 23. It is transported at regular intervals. Then, the sixth
As shown in FIG. 7 (7), the document D1 is transported along the transport path 36 by the transport rollers 34 and 35, and is returned onto the placing member 6.
The original D2 is optically scanned by the optical system 31. Manuscript D3
Is stopped in a state where the upstream end of the feeding direction 23 is pressed by the conveying roller 30. During the reading and exposing operation of the document D2, an operation of reversing the feeding direction of the document D4 is performed.

These operations are executed as needed over the originals D1 to D4 that are continuously fed.

Therefore, according to the present embodiment, the conveying force of each conveying path is individually controlled to function effectively, and the succeeding original can be fed sufficiently close to the preceding original. Therefore, the preliminary feeding of the succeeding document during the reading exposure of the preceding document can be reliably completed in a state where the preceding document is sufficiently close to the preceding document. As a result, the transport distance, that is, the transport time, which is spent for further transporting the subsequent document to the reading position, is significantly reduced. As a result, the time spent for transporting the document to the reading position over a plurality of documents is significantly reduced. Can be shortened to That is, the copying time can be remarkably reduced.

Although the present embodiment has been described in connection with the configuration of the transfer electrostatic copying machine, a configuration in which recording is performed on a recording sheet having photosensitivity, for example, may be used.

Effects of the Invention As described above, according to the present invention, it is possible to convey a succeeding sheet-like document sufficiently close to a preceding sheet-like document over a plurality of sheet-like documents continuously fed by simple control. Can be. That is, before the reading and exposure of the preceding sheet-shaped document is completed, sufficient preliminary feeding of the succeeding sheet-shaped document can be completed. Therefore, it is possible to significantly reduce the time required for transporting the subsequent sheet-shaped document on the document reading surface, and further, the time spent for transporting the document to the document reading surface across a plurality of documents. Copying time can be significantly reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a simplified configuration of a document feeder 1 according to an embodiment of the present invention, and FIG. 2 is a simplified type of a transfer type electrostatic copying machine 2 equipped with the document feeder 1. FIG. 3 is a block diagram showing an electrical configuration of the document feeder 1 and the copying machine 2, and FIG. 4 is a diagram showing a state of transport of the document D in the document feeder 1 in each copy mode. FIG. 5 is a timing chart for explaining the document feeding operation in the present embodiment, FIG. 6 is a diagram for intermittently explaining the document D feeding operation, and FIG. FIG. 11 is a cross-sectional view illustrating a simplified configuration of a conventional document feeder 201. 1. Original document feeding device 2. Copy machine 5. Transparent plate 6.
... a mounting member, 18 ... reversing means, 22 ... a first transport path,
23 ... feeding direction, 26 ... belt, 27 ... gap, 28 ... direction changing claw, 29 ... second transport path, 31 ... optical system, D ...
Original, CLT1, CLT2, CLT3 ... clutch, S1 ... first transport detector, S2 ... second transport detector, S3 ... third transport detector,
SOL1, SOL2: Solenoid, M1-M3: Motor

Claims (1)

(57) [Claims] An optical reading device in which a plurality of sheet-shaped originals fed from a placing member are transported to one branching path and then reversed in the feeding direction, and is optically read through the other branching path. In the method of feeding a sheet-like document conveyed successively and sequentially onto a document reading surface facing the means, the time when the upstream end of the preceding first sheet-like document after inversion in the feeding direction passes through the branch position of the conveyance path Stops the conveyance of the first sheet-shaped document, reverses the feeding direction of the subsequent second sheet-shaped document, and conveys the subsequent third sheet-shaped document to near the branch position. When the interval between the downstream end of the original in the feeding direction after reversal of the original and the upstream end of the stopped first sheet-shaped original in the feeding direction becomes a predetermined length, the first and second sheet-shaped originals are moved at a constant speed. Feeding of sheet-shaped originals characterized by feeding Method.