JPH10157226A - Automatic document-feeding apparatus, and image-forming apparatus with the automatic document-feeding apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten a reversing time for a document. SOLUTION: When an image of one face is completely read, a wide belt 7 is rotated in the clockwise direction, and a document P1 is discharged to a reversal feed/discharge path. The document P1 is transferred sequentially from a first reversal feed path to a second reversal feed path to a first document transfer path when a first reversing roller 17 or the like is driven. While the document P1 is transferred in the above route, the wide belt 7 is stopped driving and reversed in the counterclockwise direction. In consequence, the document P1 transferred to the first document transfer path is sent to a second document transfer path in a turned-over state, and an image of the other face is read. Since the reversed document P1 is transferred to the second document transfer path without being stopped, a reversing time is hence shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to an automatic document feeder which conveys a document to a specified position and reverses the front and back of the document conveyed to the specified position. The present invention relates to an image forming apparatus provided with an automatic document feeder.

[0002]

2. Description of the Related Art Conventionally, an automatic document feeder for properly reversing and feeding a document has been used in an image forming apparatus such as a copying machine.

For example, as is well known, a copying machine is provided with image reading means for optically reading image information of a document, and a platen is arranged on an upper surface of an apparatus main body which houses the image reading means. . The platen is configured to define the reading position (specified position) of the document while the document is placed thereon, and the image reading unit reads the image of the document at the reading position. Has become.

Further, the upper side of the apparatus main body (the upper side of the platen)
Is provided with an automatic document feeder. The automatic document feeder has a wide belt (document conveying means) which is arranged along a platen and can be driven forward and backward, and conveys a document to a reading position or unloads a document from the reading position. It is supposed to. The wide belt and the platen form a document conveyance path, and an inversion feeding path is formed so as to be continuous with the document conveyance path. A reversing roller (reversing feeding means) for conveying a document along the reversing feeding path is arranged in the reversing feeding path.

Now, when the wide belt and the reversing roller are driven while the original is placed on the platen, the original is discharged from the reading position on the platen to the reversing feed path and transported to the reading position again. Is turned over.

[0006]

By the way, skew occurs even when the original is reversed as described above, and the skew correction is performed by various methods. That is,
When the wide belt and the reversing roller are driven by different driving means, the reversing roller is stopped while the wide belt is being driven, and the leading end of the document conveyed to the reversing feed path by the wide belt is The skew is corrected by abutting against a stopped reversing roller. If the wide belt and the reversing roller are driven by the same driving means and the reversing roller cannot be stopped while driving the wide belt, another roller in the reversing feed path is used. Is stopped, and the skew of the document is corrected by abutting the leading edge of the document against the roller. Here, the rollers in the reverse feeding path are driven via a well-known one-way clutch, so that the other rollers in the reverse feeding path do not rotate in the reverse direction.

On the other hand, in order to return the original once discharged from the reading position to the reverse feeding path to the reading position, the wide belt is driven to rotate in a predetermined direction, then the driving of the belt is stopped and the belt is moved in the opposite direction. However, such belt drive control is performed when the document is stopped in the reverse feeding path.

However, if the document conveyed for reversal is stopped halfway, the time required for the reversal to end and to be placed on the platen again becomes longer, thereby increasing productivity (workability). There was a problem of lowering.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an automatic document feeder which eliminates a stoppage of a document when performing a reversing process and prevents a decrease in productivity.

Another object of the present invention is to provide an image forming apparatus which prevents a reduction in image forming speed.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and has been made to convey a document to a specified position, and to print the front and back of the document conveyed to the specified position. In an automatic document feeder for reversing, a document conveying means capable of normal / reverse drive for conveying a document to the specified position or discharging the document from the specified position, and a reversing device connected to the specified position. A feeding path, and reversing feeding means for feeding the document along the reversing feeding path to turn the document over, and driving the document feeding means in a predetermined direction. While the document is being conveyed from the defined position to the reverse feeding path, and the document is being conveyed along the reverse feeding path by the reverse feeding means, the document conveying means is driven in the opposite direction. By manuscript The conveyed to defined positions without stopping, characterized in that.

In this case, it is possible to provide a size detecting means for detecting the size of the document, and to drive the document conveying means in the opposite direction at a timing based on the detection result of the size detecting means.

According to the present invention, there is provided an image reading means for reading an image of a document at a specified position, a document being conveyed to the specified position, and front and back of the document conveyed to the specified position. And an automatic document feeder for reversing the direction of rotation, wherein the automatic document feeder conveys the document to the specified position or carries out the document from the specified position. Document feeding means, a reversing feeding path connected to the specified position, and a reversing feeding means for feeding the document along the reversing feeding path to reverse the document. And
By driving the document conveying means in a predetermined direction, the document is conveyed from the specified position to the reverse feeding path, and the document is conveyed along the reverse feeding path by the reverse feeding means. The document is transported to the specified position without stopping by driving the document transport unit in the opposite direction while the document is being stored.

In this case, it is possible to provide a size detecting means for detecting the size of the document, and to drive the document conveying means in the opposite direction at a timing based on the detection result of the size detecting means.

In addition, based on the above configuration, if the document conveying means is driven in a predetermined direction in a state where the document is at the specified position, the document is moved from the specified position to the reverse feeding path. Next, when the reverse feeding means is driven, the original is conveyed along the reverse feeding path. When the original transporting means is driven in the opposite direction while the original is being transported along the reverse feeding path by the reverse feeding means, the original passes through the reverse feeding path without being stopped. Then, the document is conveyed to the specified position, and the original is turned over.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

First, an embodiment of the present invention will be described with reference to FIG.
27 will be described with reference to FIG. <Description of Overall Configuration of Image Forming Apparatus> FIG. 1 is a cross-sectional view showing the overall configuration of an image forming apparatus G according to the present invention. A) an image input unit (hereinafter, referred to as a “reader unit”) 200 as an image reading unit that optically reads image information of a document located at a specified reading position, and a read image on a predetermined sheet material. An image output unit (hereinafter, referred to as a “printer unit”) 300 for printing,
An automatic document feeder (hereinafter, referred to as “ADF”) 2 that automatically and sequentially conveys a document to a reading position and reverses the front and back of the document conveyed to that position is disposed above the apparatus main body 1. Have been. <Explanation of the leader unit 200>
The platen 3 forms the upper surface of the apparatus main body 1 and has a document placed thereon. A scanner unit 204 having a lamp 202 and a mirror 203 is movably disposed below the platen 3. The reader unit 200 includes mirrors 205 and 206, a lens 207, an image sensor 208, and the like, and is configured to optically read image information recorded on a document, photoelectrically convert the image information, and read the image information. ing. The position control of the scanner unit 204 may be performed by controlling the driving of a well-known stepping motor, or may be performed by providing a mechanical stopper. <Description of Printer Unit 300> The printer unit 300 is a well-known image forming unit, and is not directly related to the present invention, so that detailed description is omitted. <Description of ADF2> Next, the structure of the ADF2 will be described. <Description of Document Tray> FIG. 2 is a detailed sectional view showing the structure of the ADF. The ADF 2 has a document tray 4 on which documents are placed. The document tray 4
A pair of width-direction regulating plates (not shown) are slidably arranged in the width direction of the document, and these width-direction regulating plates regulate the width direction of the document placed thereon, whereby Ensures stability during feeding.

A stopper 21 is rotatably supported at the left end of the document tray 4.
1 is a position that stands up on the tray and prevents feeding of the original (a solid line position in the drawing), and a position where the document is retracted and does not hinder the feeding (a broken line position in the drawing). Is configured to take. <Description of Each Roller and Document Conveying Path> Next, the rollers arranged in the ADF 2 and the conveying path on which the document is conveyed will be described with reference to FIGS.

FIG. 3 is a diagram showing the structure and operation of the paper feed roller 5 and the like disposed at the left end of the document tray 4.
(A) is a figure which shows the maximum raising position of the paper feed roller 5,
FIG. 4B is a diagram showing the maximum lowering position of the paper feed roller 5.
FIG. 4 is a plan view showing the structure of the paper feed roller 5 and the like.

At the left end of the document tray 4 described above, FIG.
As shown in detail in (a), a swing arm 53 that swings around a point c1 is disposed, and a feed roller 5 is rotatably supported at the tip of the swing arm 53. The swing arm 53 has a through hole 53a formed in an arc shape (the details will be described later). Further, as shown in FIG. 4, a plurality of paper feed rollers 5 are arranged along the width direction of the document.

An elevating arm 51 is arranged so as to swing about the point c1. The elevating arm 51 moves from the position shown in FIG. 3A to the position shown in FIG. 3B. It is configured to be possible. The elevating arm 51 includes support plates 51a, 51 arranged at a predetermined gap in parallel with the paper surface.
The arm shaft 51c is supported through these support plates 51a and 51b. The arm shaft 51c is inserted into the above-described through-hole 53a, and the swing arm 53
Is made to rock. In addition, the above-described support plate 5
An arm shaft 51e is supported by 1a and 51b.

On the other hand, a separation upper guide plate 52 is arranged so as to swing about the point c1, and this separation upper guide plate 52 is used when the lifting arm 51 is at the position shown in FIG. Is supported from below by an arm shaft 51e on the lifting arm side, so that clockwise rotation by its own weight is regulated. In addition, the lifting arm 51 is shown in FIG.
When the arm shaft 51e is in the position shown in FIG.
The position 2 (guide position) is defined by a stopper (not shown).

At the start of sheet feeding, the sheet feeding roller 5 is lowered until it comes into contact with the document (details will be described later). If a plurality of paper feed rollers 5 are arranged in the width direction of the document (see FIG. 4), the pressure balance between the plurality of paper feed rollers 5,.
If the feeding operation is started in the bound state, the possibility of skew of the document increases.

However, in the present embodiment, each of the feed rollers 5 has an independent suspension structure and is easy to equalize the original P, so that it is possible to improve the paper feeding performance.

On the other hand, a separation / conveyance roller 8 is rotatably supported at the rotation center c1 of the elevating arm 51, and a known separation belt 6 is disposed below the roller 8. The separating / conveying roller 8 and the separating belt 6 constitute a separating section S, and each of them is configured to rotate in the direction of an arrow to perform a document separating operation. The separation / conveyance roller 8 has a one-way mechanism, and reduces the conveyance load when a document is pulled out of the separation unit S by the first feeding roller 16 (described in detail below).

A first feed roller 16 is rotatably supported on the left side of the separation section S as shown in FIG.
The document sent from the separation unit S is transported downstream. Note that a document conveyance path between the separation unit S and the first feeding roller 16 is indicated by a symbol (a).

Further, the original conveying path (b) downstream of the first feeding roller 16 is formed to be curved to the lower left, and the second feeding roller 9 rotates in the conveying path (b). It is freely supported. The document is conveyed downstream by the second feeding roller 9. The second feed roller 9 is configured to stop driving while the original is being conveyed by the first feed roller 16, thereby forming a loop on the original and forming a loop on the original. It is designed to prevent skew.

Further, a document transport path (c) is formed from below the second feed roller 9 to the upper left of the platen 3, and a drive roller (document transport means) 36 is provided at the upper left of the platen 3. Are rotatably supported. A turn roller (document conveying means) 37, which is also rotatably supported, is disposed above and to the right of the platen 3. These rollers 36 and 37 have a width approximately equal to or larger than that of the document. A wide belt (original conveying means) 7 having a width of? The wide belt 7 is arranged along the platen 3 to form a document conveying path (d) together with the platen 3, and rotates the document P in both forward and reverse directions by a driving roller 36 to transfer the document P to the platen 3. 3. The document can be conveyed to a reading position on the printer 3 or a document can be carried out from the reading position.

That is, in this embodiment, the document transport path (a) (b) extends from the document tray 4 to the platen 3.
(C) is formed in a curved shape, and the originals P on the original tray are sequentially separated by the operation of the paper feed roller 5, the separation unit S, the first feed roller 16 and the second feed roller 9, and the like. The sheet is transported to the platen 3 above.

By the way, the above-mentioned document conveying path (C)
The second feeding roller 9 is formed so as to be curved toward the platen 3 to the lower right, but from the second feeding roller 9 to the lower left, the reverse feeding path (h) is formed to be curved. In addition, a first reversing roller (reversing feeding means) 17 is rotatably supported at the end of the feeding path (h). The reversing feeding path (h) and the above-described document conveying path (d) are connected by a reversing feeding / discharging path (e).

A reversing feed path (f) from the first reversing roller 17 extends upward and to the left, and a second reversing roller (reversing feeding means) is provided at the end of the feeding path (f). ) 18 are rotatably supported. In addition, the reversing feed path (f)
Above the second reversing roller 18, it is branched into two reversing feeding paths (R) and (G). The reversing feeding path (R) extends rightward and upward from the second reversing roller 18, and The path (g) extends toward the document transport path (b) and communicates the reverse feeding path (f) with the document transport path (b). That is,
In the present embodiment, the reverse feeding path (e) (f)
(I) and (g) are connected to the document conveying path (d), that is, the document reading position. The first reversing roller 17 and the second reversing roller 18, which are reversing feeding means, perform reversing of the document by transporting the document along the reversing feeding path (f), (i), (g). It has become.

In the present embodiment, when the original is turned upside down (pre-inversion processing) before being conveyed to the platen 3, (a) → (b) → (h) → (f) → (R) → (E) →
The document is conveyed in the order of (d) (details will be described later).

If the original is already conveyed to the platen 3 and the original has been read, and the original is turned over (inversion processing), then (e) → (f) → (g) → (c) → (c) The document is conveyed in the order of d) (details will be described later).

On the other hand, a document discharge path (nu) and a paper discharge tray 10 are disposed on the right side of the above-mentioned wide belt 7, and a paper discharge roller 12 is provided in the document discharge path (nu). Then, the document P on the platen 3 from which the image reading has been completed is discharged to the paper discharge tray 10.

On the other hand, an openable / closable manual document tray 14 is disposed above the paper discharge tray 10.
A manual paper feed roller 13 is disposed at the left end of the tray 14, and is configured to feed a document P (one document) set in the manual document tray 14 to a manual conveyance path (rule). I have. Further, a manual registration roller 11 is provided in the manual conveyance path (R), and is configured to convey the fed document to the platen 3.
The registration roller 11 is configured such that the driving thereof is stopped while the document is being conveyed, like the second feeding roller 9 described above, thereby forming a loop on the document and forming a loop. The document is prevented from being skewed.

On the other hand, a manual shutter 28 is rotatably supported on the downstream side of the manual paper feed roller 13, and the manual shutter 28 closes the manual conveyance path (l) and closes the original (the manual original tray 14). A position where the feeding of the set manual feed document) is blocked (a broken line position in the drawing) and a position where the feeding is prevented and the feeding is not hindered (a solid line position in the drawing) are
It is configured to take selectively. As a result, the original whose image has been read is transferred from the platen 3 to the discharge tray 1.
While the document is being conveyed to zero, the manual document set on the manual document tray 14 is prevented from entering the manual feeding path. The manual paper feed roller 13 is driven to rotate even while the manual document feed is blocked by the manual paper feed shutter 28, but the conveying force of the roller 13 is such that the roller 13 and the document slip. Set to low. <Explanation of Flapper> Next, the flapper arranged in each of the above-described document conveying paths will be described with reference to FIG.

A reversing sheet flapper 22 is swingably disposed at the confluence of the above-mentioned document conveying path (c), the reversing feeding path (h), and the flapper 22 is positioned at a solid line position in FIG. The document feed path (C) is closed by swinging and the reversing feed path (H) is opened, or the document feed path (H) is closed by swinging to the position indicated by a chain line in the drawing. (C) is configured to be open.

A reversing flapper 23 is swingably disposed at the junction of the reversing feeding path (i) and the reversing feeding path (g) (downstream in the conveying direction of the second reversing roller 18). The flapper 23 is swung to the solid line position in the drawing to close the reversing feed path (g) and open the reversing feeding path (g), or is swung to the position shown by the dashed line in the drawing to turn over. The feeding path (R) is closed and the reverse feeding path (G) is opened.

A one-way flapper 24 is swingably disposed at the junction of the reversing feeding path (h) and the reversing feeding / discharging path (e). In addition to serving as a guide when the document P is conveyed from the path (h) to the reversing feed path (f), the platen passes the original P from the reversing feed path (g) (f) through the reversing feed / discharge path (e). 3, the document P is prevented from going up to the reverse feeding path (h).

Further, on the platen 3 side of the reversing supply / discharge path (e), a supply / discharge flapper 25 interlocked with the reversal sheet supply flapper 22 is swingably disposed.
When the original P is transported from the reversing supply / discharge path (e) to the platen 3, the original P is swung to the solid line position in FIG. The document P from the platen 3 to the reverse supply / discharge path (e).
When the original P is conveyed, the original P
Are transported smoothly.

A paper discharge flapper 26 is arranged between the right end of the platen 3 and the manual feed registration roller 11 so as to be swingable. The flapper 26 transfers the document P from the manual feed path (L) to the platen 3. When the document P is conveyed, the leading edge of the document P which is swung to the position indicated by the solid line in FIG. When the document P is discharged, the document P is swung to the position indicated by a dashed line in the figure, so that the document P is discharged smoothly.

Further, a one-way manual flapper 27 is swingably disposed at the confluence of the original discharge path (nu) and the manual feed path (lu).
The document P to be discharged from the paper discharge tray 10 is prevented from entering the manual feed path. <Description of Driving System> Next, a driving system for driving the above-described rollers and flapper will be described with reference to FIG.

The separation conveyance roller 8 and the separation belt 6 described above
The paper feed roller 5 is configured to be rotationally driven by a DC brush motor (hereinafter, referred to as a “separation motor”) 100 that is PLL-controlled. A separation clutch 106 is interposed between the separation motor 100, the separation conveyance roller 8, the separation belt 6, and the paper feed roller 5, and the clutch 106 turns on / off the drive transmission. ing. The motor shaft of the separation motor 100 has a clock plate 100 having a plurality of slits.
a is fixed, and a separated clock sensor 100b, which is a transmission type optical sensor, is disposed at a position facing the clock plate 100a. The separation clock sensor 100b generates a clock pulse proportional to the motor rotation speed when the separation motor 100 rotates.

The second feeding roller 9, the first reversing roller 17, and the second reversing roller 18 are driven to rotate by a stepping motor (hereinafter, referred to as a "transport motor") 101 which can rotate forward and backward. It is configured. A clock plate 101a having a plurality of slits is fixedly mounted on the driven roller shaft of the second feed roller 9, and an inverted clock, which is a transmission type optical sensor, is provided at a position facing the clock plate 101a. The sensor 101b is arranged.
The inverted clock sensor 101b generates a clock pulse proportional to the rotation speed of the driven roller. If a slip occurs while the document P is being conveyed by the second feeding roller 9, the slip amount can be measured from the number of clock pulses and the number of drive clocks of the conveyance motor 101.

Further, the above-described drive roller 36 (that is, the wide belt 7) is rotatably driven by a stepping motor (hereinafter, referred to as a "belt motor") 102 which can rotate forward and backward. The belt motor 102 also includes a clock plate having a plurality of slits,
The motor rotation speed can be detected by a clock sensor which is a transmission type optical sensor.

Here, the rotation of the driving roller 36 is transmitted to the turn roller 37 by the wide belt 7, and the drive is transmitted from the turn roller 37 to the manual registration roller 11, and the conveying speed of the original on the platen 3 is changed. And the conveying speed of the manual registration rollers 11 are made equal.

The elevating arm 51 described above is configured to be driven by a stepping motor (hereinafter, referred to as a "swinging motor") 103 which can be rotated forward and backward.
In this swing motor, the number of rotations of the motor can be detected by a clock plate having a plurality of slits and a clock sensor which is a transmission type optical sensor.

Further, the discharge roller 12 and the manual feed roller 13 are FG servo-controlled DC motors (hereinafter, referred to as DC motors).
It is configured to be rotationally driven by a “paper discharge motor” 104. A clock shaft 104a having a plurality of slits is provided on the motor shaft of the paper discharge motor 104.
A paper discharge clock sensor 104b, which is a transmission type optical sensor, is disposed at a position facing the clock plate 104a. The paper discharge clock sensor 104b generates a clock pulse proportional to the rotation speed of the paper discharge motor 104 when the motor 104 rotates.

Further, the stopper 21 described above is driven by a stopper solenoid 105. Specifically, when the stopper solenoid 105 is off, the stopper 21 is at a solid line position in the figure, and when the solenoid 105 is on, a chain line position in the figure is shown. It is made to rock.

The reversing sheet feeding flapper 22 and the supply / discharge flapper 25 are driven by a path switching solenoid 107. More specifically, when the solenoid 107 is off, it is at a solid line position in the figure, and when the solenoid 107 is on. Each swings to the position indicated by the chain line in the figure.

Further, the reversing flapper 23 is driven by a reversing flapper solenoid 108. More specifically, when the solenoid 108 is off, it is at the position indicated by the solid line in the drawing.
When the solenoid 108 is on, it swings to the broken line position in the figure.

Further, the paper discharge flapper 26 and the manual feed shutter 28 are driven by a paper discharge flapper solenoid 109. Specifically, when the solenoid 109 is off, it is at the position shown by the chain line in FIG. It swings to the middle solid line position. <Description of Each Sensor> Next, each sensor will be described.

The elevating arm 51 has an elevating arm flag 51d as shown in detail in FIG.
At a position corresponding to the flag 51d (above the separation unit S), a paper feed roller home sensor 4 which is a transmission type optical sensor is provided.
5 are provided. Then, when the lift arm 51 is raised and the lift arm flag 51d blocks the sensor light path of the paper feed roller home sensor 45 as shown in the drawing, it can be detected that the lift arm 51 is at the standby position as the home position. Has become.

FIG. 3 shows a part of the swing arm 53.
As shown in detail in (a), a first swing arm flag 54 is formed, and a first swing position sensor 46 is attached to the elevating arm 51. Then, as shown in FIG. 11A, when the paper feed roller 5 comes into contact with the uppermost document, the swing position sensor 46 is shielded by the swing arm flag 54 and outputs an ON signal. As shown in FIG. 4, a second swing arm flag 55 is formed on the other swing arm 53, and a second swing position sensor 47 is disposed near the second swing arm flag 55.

Further, near the upstream portion of the stopper 21,
As shown in FIG. 2, a document set detection sensor 40, which is a transmission type optical sensor, is provided to detect that the document P has been set.

Further, in the middle of the document tray 4 (at a distance of 225 mm from the stopper 21), a document trailing edge detecting sensor (size detecting means) which is a reflection type optical sensor.
The document trailing edge detection sensor 41 can detect that a large-size document has been set.

A final original detection sensor 43, which is a reflection type optical sensor, is provided between the original set detection sensor 40 and the rear end detection sensor 41, and determines whether the original being transported is the final original. Can be determined.

Further, a paper width detection sensor 44 is provided below the document tray 4 to detect the position of the width direction regulating plate 33, and to determine the length of the document P set on the document tray 4 in the width direction. Is detected.

Further, a separation sensor 30, which is a transmission type optical sensor, is provided between the separation conveyance roller 8 and the first feeding roller 16, and the original P conveyed by the separation conveyance roller 8 is transferred. It is designed to detect. At the same position in the transport direction as the separation sensor 30 and at a predetermined distance in the thrust direction (the width direction of the document), a skew detection sensor 31, which is also a transmission type optical sensor, is provided in parallel. Along with the sensor 30, the skew amount of the fed document can be detected.

A mixed detection sensor 32 for detecting a document P by moving a flag is provided downstream of the first feeding roller 16 and in the vicinity of the roller 16. It is possible to detect that a document of a different size is set on the document tray 4 during document conveyance.

Further, on the upstream side of the second feeding roller 9 and in the vicinity of the roller 9, a paper feed sensor 35, which is a transmission type optical sensor, is provided. )
(C) and the front end and the rear end of the document P conveyed in the reverse feeding path (g).

Further, on the downstream side of the feed roller 9,
A registration sensor 39, which is also a transmission type optical sensor, is provided, and controls the stop position of the document P by detecting the rear end of the document P.

A reversing sensor 38, which is a transmission type optical sensor, is provided in the reversing supply / discharge path (e), and the document P discharged from the platen 3 or the document P entering the platen 3 is provided. Is to be detected.

Further, a reversal detection sensor 33 for detecting the document P by moving the flag is provided in the reversal feeding path (R), and the reversal flapper 23 switches the document P to the reversing feeding path (R). It is designed to detect what has been led.

Further, a manual registration sensor 34, which is a transmission type optical sensor, is provided near the downstream of the manual registration roller 11 in the sheet discharging direction, and detects a document from a manual conveyance path (L). A document P discharged from the platen 3 to a document discharge path (nu) is detected.

A manual document detection sensor 370 for detecting a document P by moving a flag is provided on the manual document tray 14 side of the manual paper feed roller 13, and detects that a document is set on the manual document tray 14. It is designed to detect. <Description of Reading Position> Next, the reading position of the document will be described with reference to FIG.

FIG. 5 is a view showing a document reading position on the platen 3, and positions of R1, R2 and R3 in the figure are set according to the document transport mode and the size of the document to be transported.

Reference numeral R1 denotes a reading position in the double-sided document mode, and the document placed at this position is read by the scanner 204 of the apparatus main body 1 for image reading.

Reference numeral R2 denotes a reading position in the half-size one-sided document conveyance mode. When the document P comes to this position R2 (hereinafter referred to as "second image destination R2"), image reading is started. ing. In this mode, the scanner 204 of the apparatus main body 1 is fixed, and reads an image while conveying a document.

A reading position R3 is a reading position in the large-size one-sided original conveyance mode and when a half-size original is vertically fed.
Image reading is started when the image reaches “third image destination R3”. Note that, even in this mode, the scanner 204 of the apparatus main body 1 is fixed, and reads an image while transporting a document.

In FIG. 5, reference numeral L1 denotes a distance from the nip point of the second feed roller 9 to the first image destination R1, and reference numeral L2 denotes a distance from the nip point of the second feed roller 9 to the second image destination R1. R
Reference numeral L3 indicates a distance from the nip point of the second feeding roller 9 to the third image destination R3. Reference numeral L4 indicates a distance from the first image destination R1 to the leading end of the original when the half-size original is placed on the left side of the platen 3, and reference numeral L5 indicates the leading end of the original stopped at the standby position and the second leading end. Symbol L6 indicates the distance from the trailing edge of the preceding document to the trailing edge of the succeeding document (inter-paper distance), and symbol L7 indicates the distance from the first image tip R1 to the manual feed registration roller 11.

Now, assuming that the length of the half-size document in the transport direction is Lph,

[0073]

Since the stop position of the half-size document is controlled such that L7 <[L4 + 2 × L6 + Lph] L2> [L5-Lph], the following document P is placed on the platen 3 as shown in FIG.
n, Pn-1 even when Pn-1 is stopped
The trailing end of the document Pn passes through the nip of the manual registration roller 11, and the trailing end of the succeeding document Pn waiting for image formation passes through the nip of the second feeding roller 9. <Description of Control Circuit> Next, the control circuit of the ADF 2 will be described with reference to FIG.

FIG. 6 is a block diagram showing a circuit configuration of the control circuit according to the present embodiment. The control circuit C is mainly composed of a microprocessor (hereinafter, referred to as “CPU”) 201, and has an RA backed up by a battery.
M (not shown) and R in which control sequence software is stored.
OM (also not shown). Reference numeral 202
Is a communication IC for controlling data communication with the copying machine main body.

The input ports of the CPU 201 include the separation sensor 30, the skew detection sensor 31, and the mixed detection sensor 3.
2, reversal detection sensor 33, manual feed registration sensor 34,
Paper feed sensor 35, reversing sensor 38, manual document detection sensor 370, registration sensor 39, document set detection sensor 40, document trailing edge detection sensor 41, final document detection sensor 4
3, paper width detection sensor 44, paper feed roller home sensor 4
5, various sensors such as the first swing position sensor 46 are connected, and are used to monitor the behavior of the document and the behavior of the movable load in the apparatus.

On the other hand, motors 100,... Are connected to output ports of the CPU 201 via drive circuits 203,.

That is, the separation motor 100 (D
The C brush motor is connected to the CPU 201 via the driver 203 and the controller 203a, and is driven and controlled by the driver 203 and the controller 203a. The controller 203a
, A reference clock serving as a reference for the motor rotation speed, an on / off signal, and the like are input from the CPU 201.

The transport motor 101 (stepping motor) is connected to the CPU 201 via a stepping motor driver 204, and is driven and controlled by the stepping motor driver 204. Further, the belt motor 102 (stepping motor) receives C through a stepping motor driver 205.
It is connected to the PU 201 and is driven by a stepping motor driver 205 at a constant current. A phase excitation signal and a motor current control signal are input from the CPU 201 to each of the drivers 204.

Further, the swing motor 103 (stepping motor) is connected to the CPU 201 via the driver 206.
, And is driven at a constant voltage by the driver 206.

The discharge motor 104 (DC brush motor) is connected to the CPU 201 via the driver 207 and the FG servo controller 207a, and is driven and controlled by the driver 207 and the FG servo controller 207a. It has become so.

Further, the stopper solenoid 105 is connected to the CPU 201 via the driver 208.
The drive is controlled by the driver 208.

Further, the separation clutch 106 is connected to the CPU 201 via a driver 209, and is driven and controlled by the driver 209.

The path switching solenoid 107 is
It is connected to the CPU 201 via the driver 210 and is driven and controlled by the driver 210.

Further, the inverted flapper solenoid 108
Are connected to the CPU 201 via a driver 211, and are driven and controlled by the driver 211.

Further, the discharge flapper solenoid 10
Reference numeral 9 is connected to the CPU 201 via a driver 212 and is driven and controlled by the driver 212.

The above-mentioned drivers 203 to 212
Are all controlled by signals input to the CPU 201.

Next, the operation of the present embodiment will be described. [1] Outline of Operation First, an outline of the operation of the present embodiment will be described with reference to FIG.

The document set detection sensor 40 detects that the document P has been set on the document tray 4, and
When the operator presses a start key (copy key) on the operation unit of the apparatus main body 1, the operation starts (main).
1).

Next, the copy mode transmitted from the apparatus main body 1 is determined (main 2), and in the case of the single-sided original mode, it is determined whether or not the original trailing edge detection sensor 41 is off (main 3). By this determination, it is possible to detect whether the document P is half size or large size. If the determination is affirmative (half size), a series of copying processes is executed in a first non-stop reading mode described later, and the operation is terminated. (Mai
n4, main9), when a negative determination (large size) is made, a series of copy processing is executed in a second flow-reading mode described later, and the operation is ended (main5, main).
n9).

On the other hand, when the copy mode transmitted from the apparatus main body 1 is determined, if the copy mode is the two-sided original mode (ma
in2), a series of copy processing is executed in the double-sided original mode, and the operation is terminated (main6, main9).

When the operator sets the manual document tray 14
When an original is set on the manual feeder,
0 outputs a signal. In this state, when the operator presses a start key (copy key) on the operation unit of the apparatus main body 1, a series of copying processes are executed in a manual feed mode described later, and the operation is terminated. (Main7, main8, mai
n9). [2] Single-sided Document Transport Mode First, the operation in the single-sided document transport mode will be described separately for the case of the half-size single-sided document transport mode and the case of the large-size single-sided document transport mode. [2-1] Half-size one-sided document transport mode First, an outline of the operation when a half-size one-sided document is transported will be described with reference to FIG.

FIG. 8 is a flowchart showing the outline of the operation.

When conveying a half-size one-sided original, first, a pickup DOWN process (details will be described later)
Is performed, the paper feed roller 5 is lowered, and is brought into contact with the document P1 (FIG. 8 draftmd1).

Thereafter, a separation process (details will be described later) is executed, and only the top original P1 is separated (see FIG. 8dra).
ftmd2), and subsequently, a paper feed process is executed (FIG. 8dr).
aftmd3).

When the document P1 is conveyed to a predetermined position on the platen 3, the document flow reading process (first flow reading mode) is executed, and the scanner 204 of the apparatus main body 1 is operated.
The document image is read while the image is fixed at a predetermined position (draftmd4 in FIG. 8).

Thereafter, the process waits until the trailing edge of the original is detected by the separation sensor 30 (draftmd5 in FIG. 8). When the detection is performed, the original set detection sensor 40 determines whether the original being transported is the last original. Yes (Fig. 8 draft
tmd6).

If the document is not the final document, a paper discharge process (details will be described later) for discharging the document P1 onto the paper discharge tray 10 is performed (draftmd8 in FIG. 8), and the above operation is repeated (draftmd2 to draftmd6 in FIG. 8).

If the original being conveyed is the last original, a paper discharge process is performed (see FIG. 8).
7), a pickup UP process (details will be described later) is performed, and the sheet feeding roller 5 is returned to the upper limit position (FIG. 8).
9), a series of processing ends.

Next, details of the operation when a half-size one-sided original is conveyed will be described with reference to FIGS. 9 and 10. FIG.

FIG. 9 is a schematic diagram showing the flow of a document when a half-size one-sided document is conveyed. FIG. 10 is a flowchart showing details of the operation when a half-size one-sided document is conveyed. .

Normally, as shown in FIG. 3A, the sheet feeding roller 5 is retracted to a position (home position) above the upper separating guide plate 52, so that the operator is obstructed by the sheet feeding roller 5. You can set a stack of originals without having to.
In the following description, the documents stacked on the document tray 4 are referred to as “document P1”, “document P2”, and “document P3” in order from the top. If the order of the originals is not specified, the original is set to “original P”.

Now, when the operator inputs copy conditions on the operation unit of the image forming apparatus and presses a start key (copy key), the document size is detected by the paper width detection sensor 44 on the platen.

The path switching solenoid 107 is turned off, the reversing sheet feeding flapper 22 is held at the solid line position in FIG. 2, the original conveying path (c) is closed, and the reversing feeding path (h) is open. However, in this mode, the path switching solenoid 107 is turned on (FIG. 10ent1), the reversing sheet feeding flapper 22 is moved to the dashed line position shown in FIG. 2, the reversing feeding path (f) is closed, and the document conveying path is closed. (C) is released.

Next, the separation motor 100 and the transport motor 10
1 and the belt motor 102 are started (FIG. 10ent).
2) The paper feed roller 5, the separation belt 6, the separation conveyance roller 8, the first feeding roller 16, the second feeding roller 9, and the wide belt 7 are driven to rotate. And the above-mentioned separation belt 6
Separation processing (details will be described later) is performed by driving the separation conveyance roller 8, and the uppermost original P1 is conveyed in the original conveyance path (A). By driving, the document P1 is transported in the document transport paths (b) and (c) (see FIG. 9A). The first feed roller 16, the second feed roller 9, and the wide belt 7
Are controlled synchronously so that their transport speeds match.

Here, the original P1 that has passed through the separation section S is
Before being conveyed by the first feeding roller 16, skew detection is performed by the separation sensor 30 and the skew sensor 31.

The paper feed roller 5 is provided with the first feed roller 1.
When the document transport by the document 6 is started, the document P is raised and separated from the document P. In the case of continuous paper feed, the paper feed roller 5
Is not raised to the home position in FIG. 3A, but is controlled to stop intermediately at a position separated from the original P1, which is the uppermost sheet, by about 3 to 5 mm (a retract position shown in FIG. 11B). . As a result, the amount of movement of the paper feed roller 5 is minimized.
The landing vibration on the top 1 is reduced, the paper feeding performance is improved, and the time until the start of the subsequent paper feeding can be shortened.

Further, when the feed roller 5 is raised as described above, the separation clutch 106 is turned off, and the driving of the separation belt 6 and the separation conveyance roller 8 is stopped. In addition, since the separation conveyance roller 8 is configured by a one-way roller, the separation conveyance roller 8 rotates following the movement of the document P1 during conveyance.

By the way, at the same time as the above-described activation of the separation motor 100 and the like (FIG. 10ent2), a size check counter counting by a clock signal input from the inverted clock is started (FIG. 10ent3).

On the other hand, when the registration sensor 39 detects the leading edge of the original, it is confirmed that the original P1 has been transported to the original transport path (C) (ent4 in FIG. 10).

When the separation sensor 30 detects the passage of the trailing edge of the document (FIG. 10ent5), the separation off counter which starts counting by the clock signal input from the separation clock is started (FIG. 10ent6). Then, when the counting for the distance L3 from the first feed roller 16 to the separation sensor 30 is completed (FIG. 10ent7), since the rear end of the document has come off from the first feed roller 16,
The separation motor 100 is turned off to stop driving the first feed roller 16 (FIG. 10ent8). At this time, skew correction described below is performed.

Further, when the paper feed sensor 35 detects the passage of the trailing edge of the original (FIG. 10ent9), the size check counter is stopped (FIG. 10ent10), and the size check processing shown in FIG.
(FIG. 10ent11).

Further, when the paper feed sensor 35 detects the passage of the trailing edge of the document (FIG. 10ent9), the registration counter counted by the belt excitation clock is started (FIG. 10ent12). This count is the distance L4 from the paper feed sensor 35 to the second feed roller 9.
When the transfer is completed for the minute (FIG. 10ent13),
01 (FIG. 10ent14), the second feeding roller 9
To stop driving. Thus, the rotation of the second feed roller 9 is stopped when the trailing end of the preceding document P1 has passed through the nip of the second feed roller 9.

On the other hand, the paper feed roller 5 is retracted to the retracted position shown in FIG. 11B, but when the trailing edge of the preceding original P1 passes the nip point of the paper feed roller 5, it falls again and the succeeding original In preparation for the sheet feeding operation of P2. Then, the preceding original P1
When the trailing end of the sheet has passed through the nip point of the first feeding roller 16, the separation clutch 106 is turned on, and the feeding of the succeeding document P2 by the sheet feeding roller 5 is started (see FIG. 9A).

The rotation of the second feed roller 9 is stopped when the trailing end of the preceding document P1 has passed through the nip of the second feed roller 9 as described above. Since the feeding of the subsequent document P2 is performed at a high speed, when the rotation of the second feeding roller 9 is stopped, the leading edge of the following document P2 is located near the upstream of the second feeding roller 9 (feeding sensor). (The position where 35 is disposed). When the leading edge of the succeeding document P2 is detected by the paper feed sensor 35, control for skew feeding is performed as in the case of the preceding document P1.

On the other hand, the preceding original P1 has entered the original conveying path (d) on the platen 3 and is independently conveyed by the wide belt 7. However, the belt motor 102 operates at the time when the above-mentioned registration counter is completed. (Fig. 10en
At t15), the operation is stopped (FIG. 10ent16). As a result, the preceding document P1 is temporarily stopped when its trailing end has advanced a predetermined distance after passing through the nip point between the paper feed sensor 35 and the second feeding roller 9 (see FIG. 9B). That is, the distance L8 (see FIG. 9B) between the rear end of the preceding document P1 and the nip point of the second feed roller 16 is:

[0116]

L2 = L2-L5-conveyed document size L2; distance from second image destination position R2 to nip point of second feed roller 9 L5; distance from second image destination position R2 to leading edge of preceding original P1 When the preceding document P1 is temporarily stopped as described above, since the trailing end of the preceding document P1 has passed through the nip point of the second feed roller 16, the value of L8 is positive (plus ).

At the same time when the driving of the belt motor 102 is stopped (FIG. 10ent16), the path switching solenoid 107 is turned off (FIG. 10ent17).

When the document P1 is once stopped, the control circuit C outputs a transport completion signal to the apparatus main body 1 and waits for a transport start signal from the apparatus main body 1 to be input.

When the skew feed control of the succeeding document P2 is completed and the control circuit C receives the transport start signal from the apparatus main body 1, the control circuit C activates the wide belt 7 to activate the preceding document P2. P1 is transported at the image forming speed.

During this time, the driving of the second feed roller 9 is stopped and the succeeding document P2 is on standby, but the distance between the trailing edge of the preceding document P1 and the leading edge of the succeeding document P2 (hereinafter referred to as the sheet distance) ) Reaches a predetermined distance, the second feed roller 9 is activated, and the succeeding document P2 is conveyed at the same image forming speed as the preceding document P1. The activation and the transport speed of the second feed roller 9 are controlled such that the transport speed of the wide belt 7 and the transport speed of the second feed roller 9 match at the time when the above-mentioned paper interval becomes L6. Is done.

Then, the preceding original P1 is shifted to the second image destination position R2.
, The control circuit C outputs an image destination reaching signal to the apparatus main body 1, and the apparatus main body 1 receives the
Of the image reading (first moving reading mode) is started.

In this mode, the scanner 2
Reference numeral 04 denotes a position where the scanner 204 does not face the document P1 when the rear end of the document P1 is in contact with the second feeding roller 9. That is, the scanner 2
Reference numeral 04 denotes a case where the length of the document in the feeding direction is La mm, and the distance from the second feeding roller 9 to the position of the scanner 204 (the distance along the document feeding paths (c) to (d)) is Lb. ,

[0123]

[Formula 3] A position satisfying the relationship of La <Lb (for example, the second image destination position R2
And the third image destination position R3).

When reading of the image of the original P1 is completed,
The document is stopped at a position where the rear end of the document and the second image front position R2 are at a predetermined distance L9 (see FIG. 9C). At this time, in the subsequent document P2, the leading edge of the document and the second image tip position R2 are separated by a predetermined distance L.
5, and the document P3
Are waiting in a state where a loop for skew removal is formed by the stopped second feeding roller 9.

When a conveyance start signal is input from the apparatus main body 1 in this state, the control circuit C activates the wide belt 7 (belt motor 102) to start conveyance of the succeeding document P2 (see FIG. 9D). ), The apparatus main body 1 reads an image of the document P2.

In the meantime, the paper discharge process (details will be described later) of the preceding document P 1 is performed, and the document is discharged onto the paper discharge tray 10.

The details of each of the above-described processes will be described below. <Pickup DOWN Processing> Here, the pickup DOWN processing will be described with reference to FIG.

When the paper feed roller 5 is at the home position (see FIG. 3A), the paper feed roller home sensor 4
5 is on. In this state, when the swing motor 103 is driven to lower the lift arm 51 and the swing arm 53 (pickupdwn1), the paper feed roller home sensor 45 is turned off (pickupdwn2). further,
When the lifting arm 51 and the swing arm 53 are lowered, the swing position sensor 46 is shielded by the swing arm flag 54 and outputs an ON signal in a state where the paper feed roller 5 is in contact with the uppermost document P1 ( pickupwn3), and stops driving the swing motor 103 based on the ON signal (p.
ickupdwn4). In this state, the paper feed roller 5
The original P1 comes into contact with the original P1 by its own weight, and a stable feeding force is always applied to the original P1 (see FIG. 11A).

If the elevating arm 51 is lowered even after the paper feed roller home sensor 45 is turned off (pickupdwn2) as described above, the engagement between the arm shaft 51c and the swing arm 53 is released, and the swing arm 53 is released. The relative positional relationship between the moving arm 53 and the elevating arm 51 starts to shift, but the elevating arm 51 is turned on by the swing position sensor 46.
Since the stop is performed based on the signal, the shift amount is constant (see FIG. 11A). <Separation processing and skew correction> Here, the separation processing and skew correction will be described with reference to FIG.

When the separation motor 100 is driven as described above (separ 1 in FIG. 13), the separation belt 6 and the separation conveyance roller 8 are driven to rotate in the directions of the arrows, respectively, so that the document P conveyed from the document tray 4 is one sheet. Each document is separated and further transported to the downstream document transport path (b). When the leading end of the document P1 reaches a predetermined position on the downstream side of the separation / conveyance roller 8, the separation sensor 30 is turned on (FIG. 13 sep.).
a2) The remaining transport distance and the separation sensor 30 until a loop is formed by abutting the leading edge of the document against the second feeding roller 9 so that the separation process is completed within a predetermined time range.
The speed of the separation motor 100 is controlled based on the elapsed time until the power is turned on (sepa3 in FIG. 13).

When the leading edge of the document P1 is detected by the paper feed sensor 35 arranged near the upstream side of the second feed roller 9 (sepa4 in FIG. 13), the separation is counted by the clock signal input from the separation clock. The loop counter is started (sepa5 in FIG. 13), and the driving of the separation motor 100 (the driving of the first feeding roller 16)
After the end of the set count, the operation is stopped (see FIG.
6, sepa7). As a result, the leading end of the document P1 is abutted against the nip portion of the stopped second feeding roller 9, and the document P1 is stopped in a state where a predetermined amount of loop is formed. <Size Check Process> Here, the size check process will be described with reference to FIG.

In this size check processing, the original document size is corrected by adding the distance from the nip position of the second feed roller 9 to the paper feed sensor 35 to the size check counter data as the document size determining means. (Length in the feed direction). At this time, the original is fed to the second feeding roller 35.
And the wide belt 7, and the feed amount and the count value by the belt excitation clock surely coincide with each other. Thereafter, A5 and B are used according to the corrected size data.
5, size determination of A4, B5R, A4R, B4, A3, etc. is performed. <Original Reading Process> Here, the original reading process will be described with reference to FIG.

The belt motor 102 is started (see FIG. 15 mo).
ve1) When the wide belt 7 is driven, the document P1 is conveyed along the platen 3 as described above. Simultaneously with the activation of the belt motor 102, an image-on-counter that is counted by the belt excitation clock is started (move2 in FIG. 15). Note that the belt motor speed at this time is based on the speed reading speed data (V) received from the apparatus main body 1.
The constant speed control is performed by outputting the excitation clock signal based on Then, when the counting of the image destination on-counter is completed (move 3 in FIG. 15), the image signal is transmitted to the apparatus main body 1.
(See move4 in FIG. 15).

After receiving the image tip signal, the apparatus main body 1 performs actual control of the time required for the leading edge of the document to reach the optical system fixed position at the time of moving reading to perform actual image reading.
Specifically, the scanner 204 is activated, and the scanner 2
At step 04, a document image is read.

The image tip signal is turned off after a predetermined time has elapsed (see Moves 5, 6, 7 in FIG. 15), and the reading of the original image is completed. When the rear end of the document has passed the reading position, the belt motor 102 is turned off (FIG. 15).
move8).

[0136] Also, the drifting speed data (V) is
It may be equal to or different from the reading speed (V1) when the optical system moves. In particular, when V> V1, the reading of the original image is completed in a shorter time than the normal optical system moving reading, so that the copying speed is improved. <Pickup UP processing> Here, this pickup U
The P process will be described with reference to FIG.

The swing motor 103 is connected to a pickup DOW
When rotationally driven in the direction opposite to that during N processing (see FIG. 16 pick)
up1), the paper feed roller 5 is raised via the lifting arm 51 and the swing arm 53. Then, the drive of the swing motor 103 is stopped by turning on the paper feed roller home sensor 45 (FIG. 16: pickup2, pickup).
up3), the paper feed roller 5 is held at the upper limit position. <Discharge Processing> Here, the discharge processing will be described with reference to FIG.

When the belt motor 102 is started as described above, the wide belt 7 and the manual registration roller 11 are driven to rotate. Here, this manual registration roller 1
1 is driven at a transport speed equal to the transport speed of the wide belt 7. The discharge motor 104 is started together with the start of the belt motor 102 (ejct1 in FIG. 17), and the discharge roller 12 and the manual feed roller 13 are driven to rotate. Here, the discharge roller 12 is driven at a transport speed equal to or slightly higher than the transport speed of the wide belt 7.

On the other hand, the discharge flapper solenoid 109 is in the off state, and the tip of the discharge flapper 26 is located lower than the platen 3 as shown by the chain line in FIG. Therefore, the preceding original P1 on the platen 3 is
The sheet is conveyed by the wide belt 7, the manual registration roller 11, and the paper discharge roller 12 through the document conveyance path (d) to the document discharge path (nu), and is discharged onto the paper discharge tray 10.

By detecting the leading edge of the discharged original P1 by the manual feed registration sensor 34, it is confirmed that the original P1 is being conveyed along the original discharge path (nu) (see FIG. 17 eject).
2) When the sensor 34 detects the rear end of the original P1 and confirms that the rear end of the preceding original P1 has passed through the nip of the manual registration roller 11 (see FIG. 17ejct).
3), the driving of the belt motor 102 is stopped (FIG. 17).
ejct4). As a result, the driving of the wide belt 7 and the manual registration roller 11 is stopped, and the document P1 is independently conveyed by the discharge roller 12 and the like. At this point, the image reading of the subsequent document P2 has been completed, and the subsequent document P2 is stopped on the platen 3 together with the subsequent document P3 (FIG. 9).
(E)).

At the same time as the driving of the belt motor 102 is stopped, a paper discharge counter for counting by a clock signal input from the paper discharge clock is started (see FIG. 17ejc).
t5) After the end of the set count (see FIG. 17ejct).
6), the driving of the paper discharge motor 104 is stopped (FIG. 17e)
jct7). As a result, the driving of the paper discharge roller 12 and the manual paper feed roller 13 is stopped, but at this point, the document P1 has already passed through the document discharge path (nu) and has been discharged.
2 and is discharged onto the discharge tray 10. [2-2] Large-size one-sided document transport mode First, the outline of the operation when a large-size one-sided document is transported will be described with reference to FIG.

FIG. 18 is a flowchart showing an outline of the operation.

When a large-sized one-sided document is conveyed, first, the above-described pickup DOWN processing is performed, and the paper feed roller 5 is lowered to come into contact with the document P1 (FIG. 18 draft2md1).

Thereafter, the above-described separation processing is executed to separate the uppermost original P1 by one sheet (draft2 in FIG. 18).
md2), and subsequently, a sheet feeding process is executed (FIG. 18dra).
ft2md3). The operation up to this point is the same as that in the case of the half-size one-sided document transport mode described above.

When the document P1 is conveyed to a predetermined position on the platen 3, the document flow reading process (second flow reading mode) is executed, and the scanner 204 of the apparatus main body 1 is operated.
The original image is read while the image is fixed at a predetermined position (draft2md4 in FIG. 18). In this mode, since the scanner 204 is fixed at the third image destination position R3 near the paper discharge tray 10, as a result, the above-described document flow reading processing and paper discharge processing are performed continuously. This means that the document P1 from which the image has been read is discharged onto the discharge tray 10 (FIG. 18Draft2md5).

Thereafter, the process waits until the separation sensor 30 detects the trailing edge of the document (draft2md6 in FIG. 18).
When the detection is performed, it is determined by the document set detection sensor 40 whether the document being transported is the last document (FIG. 18D).
raft2md7).

If the document is not the final document, the above operation is repeated (FIG. 18: draft2md2 to draft2m).
d7) If it is the last document, the pickup UP process is performed to return the sheet feeding roller 5 to the upper limit position, and a series of processes is ended (FIG. 18 draft2md8).

Next, details of the operation when a large-sized one-sided original is conveyed will be described with reference to FIG.

FIG. 19 is a schematic diagram showing the flow of a document when a large-sized one-sided document is conveyed.

Operation from Pickup DOWN Processing to Feeding Processing (FIG. 18: draft2md1 to draft2md)
3) is the same as in the case of the half-size one-sided document transport mode described above.

That is, also in the present mode, the path switching solenoid 107 is controlled to be turned on in the same manner as in the above-described half-size one-sided original transport mode, and the reverse feeding path (f).
Is closed and the document transport path (C) is opened. The wide belt 7 is driven when the preceding document P1 is transported, and has a transport speed equal to that of the second feed roller 9 before the preceding document P1 enters the platen 3. Therefore, the preceding original P1 is transported to the platen 3 through the original transport path (C) by the above-mentioned two rollers 16, 9 and the wide belt 7 (see FIG. 19A).

The rotation of the second feed roller 9 is stopped when the trailing end of the preceding original P1 has passed through the nip of the second feed roller 9.

On the other hand, the paper feed roller 5 is retracted to the retract position after feeding the preceding original P1,
When the trailing end of the sheet 1 passes through the nip point of the sheet feeding roller 5, it descends again to prepare for the operation of feeding the succeeding document P2. When the trailing edge of the preceding document P1 passes through the nip point of the first feed roller 16, the separation clutch 106 is turned on, and the feed roller 5
Of the subsequent document P2 is started (FIG. 19A)
reference).

By the way, the rotation of the second feed roller 9 is stopped when the trailing edge of the preceding document P1 has passed through the nip of the second feed roller 9 as described above. Since the feeding of the subsequent document P2 is performed at a high speed, when the rotation of the second feeding roller 9 is stopped, the leading edge of the following document P2 is located near the upstream of the second feeding roller 9 (feeding sensor). (The position where 35 is disposed). When the leading edge of the succeeding document P2 is detected by the paper feed sensor 35, control for skew feeding is performed as in the case of the preceding document P1.

On the other hand, the preceding document P1 has entered the document conveying path (d) on the platen 3, is conveyed alone by the wide belt 7, and the rear end thereof is the nip between the paper feed sensor 35 and the second feeding roller 9. When the vehicle travels a predetermined distance after passing through the point, the vehicle temporarily stops (see FIG. 19B). That is, the distance L10 (see FIG. 19B) between the rear end of the preceding document P1 and the nip point of the second feed roller 16 is:

[0156]

L10 = L3-L5'-Conveyance Document Size L3; Distance from Third Image Destination Position R3 to Nip Point of Second Feeding Roller 9 L5 '; Top of Original Document P1 from Third Image Destination Position R3 When the preceding document P1 is temporarily stopped as described above, the rear end of the preceding document P1 has passed through the nip point of the second feeding roller 16, so that the value of L10 is positive. (Plus).

When the document P1 is once stopped, the control circuit C outputs a transport completion signal to the apparatus main body 1 and waits for a transport start signal to be input from the apparatus main body 1.

When the skew feed control of the succeeding document P2 is completed and the control circuit C receives the conveyance start signal from the apparatus main body 1, the control circuit C activates the wide belt 7 to move the preceding document P2. P1 is transported at the image forming speed.

During this time, the second feed roller 9 remains stopped and the succeeding document P2 is on standby, but the distance between the trailing edge of the preceding document P1 and the leading edge of the succeeding document P2 (hereinafter referred to as the sheet distance) ) Reaches a predetermined distance, the second feed roller 9 is activated, and the succeeding document P2 is conveyed at the same image forming speed as the preceding document P1. The activation and the transport speed of the second feed roller 9 are controlled so that the transport speed of the wide belt 7 and the transport speed of the second feed roller 9 match at the time when the above-mentioned sheet distance becomes L11. (FIG. 19C)
reference).

Then, the preceding original P1 is shifted to the third image position R3.
, The control circuit C outputs an image destination reaching signal to the apparatus main body 1, and the apparatus main body 1 receives the
Image reading is started.

When the image reading of the preceding document P1 is completed, the wide belt 7 is driven for a predetermined time and then stopped, and the subsequent document P2 is conveyed to the position shown in FIG. Stopped. In addition, the sheet distance L1
1 denotes a manual registration roller 11 from the leading end of the succeeding document P2.
Is set to be larger than the distance to the nip point of the preceding original P2 when the succeeding original P2 stops.
The rear end of the document 1 has passed the nip point of the manual registration roller 11, and the document P <b> 1 is independently conveyed and discharged by the discharge roller 12. [3] Double-sided Document Transport Mode Next, the operation in the double-sided document transport mode will be described separately for the case of the half-size double-sided document transport mode and the case of the large-size double-sided document transport mode. [3-1] Half-size double-sided document transport mode First, an outline of the operation when a half-size double-sided document is transported will be described with reference to FIG.

When a half-size double-sided document is conveyed, the above-described pickup DOWN processing is executed, and the paper feed roller 5 is lowered to abut on the document P1 (dou).
blemd1). Thereafter, the above-described separation processing is executed, and only the topmost document P1 is separated and fed (do
ublemd2). The operation up to this point is the same as in the case of the single-sided document transport mode described above.

Next, a pre-reversal process is performed, and the front and back of the document P1 is reversed (doubled3), and the reversed document P1 is placed on the platen 3 with the second surface facing down. Then, the optical system moving document reading is executed (d
reading 4), reading of the original image on the second side
This is performed while moving the scanner 204 of the apparatus main body 1.

When the reading of the document is completed, the reversing process is performed using the reversing supply / discharge path (e), the reversal feeding path (g), and the document conveying path (c) (doublebled5).
Thereafter, the original image on the first side is read (dou).
blemd6).

While such a reading process is being performed, the document set detection sensor 40 determines whether or not the document is the last document (doubled 7). If the document is not the last document, a paper discharge process for discharging the document P1 onto the paper discharge tray 10 is performed (doubled8), and the above operation is repeated (doublebled2 to doublebled).
7). If the original is the last one, the paper discharge process is performed (doubled 9), the pickup UP process is performed, and the paper feed roller 5 is returned to the upper limit position (double).
md10), a series of processing ends.

Next, details of the operation when a half-size double-sided document is conveyed will be described with reference to FIGS. 21 and 22.

FIG. 21 is a schematic diagram showing the flow of a document when a half-size double-sided document is conveyed.
FIG. 7 is a flowchart illustrating details of an operation when a half-size double-sided document is conveyed.

Now, when the operator inputs copy conditions on the operation unit and presses a start key (copy key), the separation motor 100 and the transport motor 101 are started (FIG. 22).
pretrn1). Thereby, the first feeding roller 16,
The second feeding roller 9, the first reversing roller 17, and the second reversing roller 18 are driven to rotate, and the above-described separation processing and skew correction are performed.

At the same time as the start of the separation motor 100 and the like, a size check counter counting by a clock signal input from the inverted clock is started (pretrn2 in FIG. 22).

On the other hand, in this mode, when the path switching solenoid 107 is off,
Reference numeral 2 is held at the solid line position in FIG. 2 to close the document conveying path (C) and open the reverse feeding path (H). Also,
With the reversing flapper solenoid 108 turned off, the reversing flapper 23 is held at the solid line position in FIG. 2 to close the reversing feed path (G) and open the reversing feed path (G). Therefore, when the second feeding roller 9 is driven to rotate, the original P1 whose front end is abutted against the second feeding roller 9 is guided to the reversing feeding path (H), (F), and (R). Then, a pre-inversion process is performed (see FIG. 21A). Whether or not the document P1 has been conveyed to the reverse feeding path (h) is confirmed by detecting the leading edge of the document by the registration sensor 39 (pretrn3 in FIG. 22).

On the other hand, when the separation sensor 30 detects the passage of the trailing edge of the original (pretrn4 in FIG. 22), the separation off counter which starts counting by the clock signal input from the separation clock is started (pretrn5 in FIG. 22).
Then, when the counting for the distance L3 from the first feeding roller 16 to the separation sensor 30 is completed (FIG. 22 pre
trn6), since the trailing end of the original is removed from the first feed roller 16, the separation motor 100 is turned off to stop driving the first feed roller 16 (pretrn7 in FIG. 22).

When the paper feed sensor 35 detects the passage of the rear end of the original (pretrn8 in FIG. 22), the size check counter is stopped (pretrn9 in FIG. 22).
A size check process is performed based on the data (FIG. 2).
2pretrn10).

Further, when the registration sensor 39 detects the passage of the trailing edge of the original (pretrn11 in FIG. 22), the pre-inversion counter counted by the inversion excitation clock is started (pretrn12 in FIG. 22). And
When the pre-reversal counter ends (pretr in FIG. 22)
n13), the transport motor 101 is turned off (FIG. 22 pre
trn14). Thus, the document P1 is stopped at a predetermined position where the trailing end of the document P1 has passed through the reverse feeding path (h).

After a lapse of a predetermined time from the turning off of the transport motor 101, the transport motor 101 is started in the reverse direction, and the first reversing roller 17 and the second reversing roller 18 are driven to rotate in the reverse direction. The motor 102 is started to rotate the wide belt 7 in the forward direction (FIG. 22).
pretrn15). As a result, the document P1 is guided to the document conveying path (d) on the platen 3 through the reversing supply / discharge path (e) (see FIG. 21B).

When the original P1 is conveyed from the original conveying path (b) to the reverse feeding path (h), (f), and (i), the rear end of the original P1 has passed through the one-way flapper 24. At times, the supply / discharge flapper 25 has been moved to the solid line position in FIG. Therefore, when the pre-reversed document P1 is conveyed to the document conveyance path (d) through the reversing supply / discharge path (e), the front end of the document P1 is prevented from colliding with the end of the platen 3. . The transport speed of the first reversing roller 17 and the like and the transport speed of the wide belt 7 are controlled to be constant except for special cases.

On the other hand, it is confirmed that the document P1 has been conveyed to the reversing supply / discharge path (e) based on the passage of the leading edge of the document by the reversing sensor 38 (pretrn16 in FIG. 22), and the reversing sensor 38 detects Is detected (Fig. 2
2 pretrn17), the drive of the transport motor 101 is stopped (pretrn18 in FIG. 22).

Further, based on the detection signal of the reversing sensor 38 (the signal which detects the rear end of the original), the pre-feed counter which is counted by the belt excitation clock is started (pretrn19 in FIG. 22). Then, when the pre-feed counter has finished counting (pret in FIG. 22).
rn20), the driving of the belt motor 102 is stopped (FIG. 22 pretrn21). Thereby, the driving of the wide belt 7 is stopped, and the document P1 is stopped at a predetermined position on the platen 3 with the second surface facing down (FIG. 21).
(C)).

In this state, the scanner 204
Are scanned, and an image on the second surface of the document P1 is read.

When the reading of the image on the second side of the document P1 is completed, the document is reversed. Here, the inversion processing will be described with reference to FIG.

The reversing flapper 23 is held at the solid line position in FIG. 2 to close the reversing feed path (G) and open the reversing feed path (R) as described above. When performing the operation, the reversing flapper solenoid 108 is turned on (trn1 in FIG. 23), the reversing flapper 23 is switched to the chain line position in FIG. 2, and the reversing feeding path (g) is opened and the reversing feeding path (g) is closed. I do.

Also, the path switching solenoid 107 is turned on (trn1 in FIG. 23), the reverse sheet feeding flapper 22 is held at the chain line position in FIG. It closes and holds the supply / discharge flapper 25 at the position indicated by the chain line in FIG.

Next, the belt motor 102 is started to drive the wide belt 7 to rotate clockwise (see FIG. 23 tr).
n2) The document P1 is conveyed from the reading position on the platen to the reverse supply / discharge path (e). Further, the transport motor 101 is started to activate the second feeding roller 9, the first reversing roller 17, and the second
The reversing roller 18 is driven to rotate clockwise (see FIG. 2).
3trn2), the document P1 is transported along the reverse feeding path (f) and (g) and the document transport path (c) (see FIG. 21D).

When the document P1 on the platen 3 is discharged to the reversing supply / discharge path (e), the leading end of the document is detected by the reversing sensor 38 (trn3 in FIG. 23).
At the same time as this detection, an inversion counter counted by the belt excitation clock is started (trn in FIG. 23).
4). When the count of the reversal counter is completed, the belt motor 102 is turned off (trn5, t23 in FIG. 23).
rn6), and after a lapse of a predetermined time, is driven to rotate counterclockwise (trn7 in FIG. 23). Therefore, the document P1 conveyed to the document conveying path (c) is guided to the document conveying path (d) by the wide belt 7. The stop of the driving of the wide belt 7 and the driving in the opposite direction are performed in the first direction.
The original P is rotated by the reversing roller 17 and the second reversing roller 18.
1 is carried out while conveying. Therefore, the document P1 is
The document is conveyed to the reading position of the document conveying path (d) without stopping. The transport speed of the wide belt 7 is set to the second speed by the time the leading edge of the document P1 enters the document transport path (d).
Control is performed so as to match the transport speed of the feed roller 9.

Further, the paper feed sensor 35 detects the passage of the leading edge of the original to confirm that the original P1 is being conveyed through the reverse feeding path (g) (trn8 in FIG. 23), and the registration sensor 39 detects that the original is behind the original. When the passage of the edge is detected (trn in FIG. 23)
9), the transport motor 101 is turned off (trn1 in FIG. 23).
0). Thus, the rotation of the second feed roller 9 is stopped when the trailing end of the preceding document P1 has passed through the nip of the second feed roller 9. Therefore, the preceding document P1 that has entered the document conveying path (d) is conveyed independently by the wide belt 7.

Further, at the same time when the feed sensor 35 detects the passage of the rear end of the original, a reverse feed counter counted by the belt excitation clock is started (FIG. 23).
trn11). Then, when the counting of the reversing sheet feeding counter is completed (trn12 in FIG. 23), the belt motor 1
02 is turned off (trn13 in FIG. 23). This allows
The driving of the wide belt 7 is stopped, and the document P1 is stopped at a predetermined position on the platen 3.

At this position, the scanner 204
Are scanned, and an image on the first surface of the document P1 is read.

Thereafter, the reversing flapper solenoid 108 is turned off to switch the reversing flapper 23 to the solid line position in FIG. 2, and the path switching solenoid 107 is turned off to move the reversing sheet feeding flapper 22 and the supply / discharge flapper 25 to the solid line positions in FIG. (Trn14 in FIG. 23).

In the reversing process, the wide belt 7 is driven to rotate in the forward direction (trn7 in FIG. 23).
The original P1 is driven by the first reversing roller 17 and the wide belt 7.
However, since the nip force of the first reversing roller 17 is stronger, the document P1 is conveyed by the reversing roller 17. However, in the case of a large-sized document (a document that is long in the feed direction), the transport force of the wide belt 7 may be greater, and smooth transport of the document may be hindered. Therefore, in this case, the wide belt 7 is driven in the opposite direction at a timing based on the detection result of the size detecting means such as the document trailing edge detection sensor 41.

On the other hand, before and after the detection of the trailing edge of the preceding document P1 by the sheet feeding sensor 35, the sheet feeding roller 5 and the separation unit S are driven to separate and feed the succeeding document P2 from the document tray 4 and the second document P2. The skew feeding is performed by the feeding roller 9. Then, the second feed roller 9, the first reversing roller 17, and the second reversing roller 18 are driven to perform a pre-reversal process for the succeeding document P2 (see FIG. 21E). Note that the subsequent document P2
Indicates that the pre-reversal process is completed while the image of the preceding document P1 is being read, and the leading end of the pre-reversal process is moved to the first reversing roller
Waiting in a nip state.

When the image reading of the preceding original P1 is completed, the first reversing roller 17 and the second reversing roller 18
Of the wide original belt 7 and the forward rotation of the wide belt 7 are started.
And the subsequent document P2 is placed on the platen 3 at a predetermined paper distance L.
They are placed at a distance of 12 (see FIG. 21 (f)).

In this state, the scanner 20 of the apparatus main body 1 is
4 is scanned, and the image on the second surface of the succeeding document P2 is read.

When this image reading is completed,
As in the case of the preceding document P1, the reversing process of the succeeding document P2 starts, and the succeeding document P2 is discharged to the reversing supply / discharge path (e). The preceding document P1 is conveyed in the direction of the reversing supply / discharge path (E) with this reversing process. However, since the sheet distance L12 is set to an appropriate value, the reversal supply / discharge path (E) is set. , And remains on the platen 3 without being discharged.

Thereafter, the wide belt 7 is driven to rotate in the reverse direction, and the subsequent document P2 is moved through the reverse feeding / discharging path (e), the reverse feeding path (f), the reverse feeding path (g), and the document feeding path (c). The document is then guided to the document transport path (d).

The wide belt 7 is stopped in the state shown in FIG. 21 (g), and the image on the first surface of the succeeding document P2 is read in this state. At this time, the distance between the document P1 and the document P2 is L13. Further, the following original P3
Are on standby while being fed from the document tray 4 and nipped by the first reversing roller 17.

When the reading of the image on the first side of the succeeding document P2 is completed, the first reversing roller 17 and the second reversing roller 18
, The wide belt 7 rotates forward, and the paper discharge roller 12 starts rotating, and the subsequent documents P3 and P2 and the preceding document P1 are simultaneously conveyed to the paper discharge tray 10 side.

When the succeeding original P3 is placed on the platen 3, the wide belt 7 is stopped, and the subsequent original P3 is stopped.
(See FIG. 21H). At this time, since the trailing end of the preceding document P1 has already passed through the nip of the manual registration roller 11, the preceding document P1 is independently conveyed by the discharge roller 12 and discharged to the discharge tray 10.

When reading a plurality of originals, the above-described operation is repeated. However, when the final image reading (ie, the image reading of the first side of the final original Pn) is completed, the platen 3 Two originals (final original Pn and final previous original Pn-1) are placed on the top. These originals Pn and Pn-1 are continuously discharged to the discharge tray 10 by driving the wide belt 7. [3-2] Large-size double-sided document transport mode Next, the operation when a large-size double-sided document is transported will be described with reference to FIG.

FIG. 24 is a schematic diagram showing the flow of a document when a large-sized double-sided document is conveyed.

Also in this mode, as in the case of the half size, the reversing sheet feeding flapper 22 is held at the solid line position in FIG. 2 to close the document conveying path (C) and open the reversing feeding path (H). The inversion flapper 23 is held at the solid line position in FIG. 2 to close the inversion feeding path (g) and open the inversion feeding path (g).

Now, when the operator inputs copy conditions on the operation unit and presses a start key (copy key), the separation motor 100 and the conveyance motor 101 are started to perform separation processing and tilting, as in the case of half size. Row correction is performed.

The original P1 is fed in the reverse feeding path (h).
(F) Pre-reversal processing is performed by being guided to the side of (i) (see FIG. 24 (a)), and the rear end has passed through the reverse feeding path (h) based on the stop of the transport motor 101. Stopped in position.

Next, after a lapse of a predetermined time after the conveyance motor 101 is stopped, the motor 101 is started in the reverse direction, and the first reversing roller 17 and the second reversing roller 18 are driven to rotate in the opposite directions. Then, the belt motor 102 is activated to rotate the wide belt 7 in the forward direction. As a result, the document P1 is guided to the document transport path (d) on the platen 3 through the reverse supply / discharge path (e) (see FIG. 24B). At this time, since the supply / discharge flapper 25 has been moved to the position indicated by the solid line in FIG. 2, it is possible to prevent the leading end of the document P1 from colliding with the end of the platen 3. The transport speed of the first reversing roller 17 and the like and the transport speed of the wide belt 7 are controlled to be constant except for special cases.

When the rear end of the document P1 is detected by the reversing sensor 38, the driving of the wide belt 7 is stopped after a predetermined time has elapsed, and the document P1 is placed at the image position in the fixed reading mode (FIG. 24). (C)).

In this state, the scanner 204
Are scanned, and an image on the second surface of the document P1 is read.

When the reading of the image on the second side of the original P1 is completed, the original is reversed.

That is, the reversing flapper 23 is switched to the position indicated by the chain line in FIG. 2 to open the reversing feeding path (g) and close the reversing feeding path (g).
Is held at the chain line position in FIG. 2 to open the original conveying path (C), close the reverse feeding path (H), and
5 is held at the position indicated by the chain line in FIG.

On the other hand, when the above-described image reading is completed, the belt motor 102 and the transport motor 101 are started, and
Wide belt 7, second feeding roller 9, first reversing roller 17
The second reversing roller 18 is driven to rotate in the reverse direction. As a result, the document P1 is transported through the reverse feeding / discharging path (e) → the reverse feeding path (f) to (g) → the document feeding path (c) (FIG. 2).
4 (d)). Thereafter, the document P1 is guided to the document conveying path (d) via the document conveying path (c).

When the original P1 on the platen 3 is discharged to the reversing supply / discharge path (e), the leading end of the original is detected by the reversing sensor 38, but after a lapse of a predetermined time from the detection timing, The driving of the wide belt 7 is stopped, and then the wide belt 7 is rotated in the forward direction. Therefore, the document P1 conveyed to the document conveying path (c) is guided to the document conveying path (d) by the wide belt 7. The transport speed of the wide belt 7 is controlled so as to match the transport speed of the second feed roller 9 by the time the leading edge of the document P1 enters the document transport path (d).

The rotation of the second feed roller 9 is stopped when the trailing edge of the preceding original P1 has passed through the nip of the second feed roller 9.

The preceding document P1 that has entered the document conveying path (d) is independently conveyed by the wide belt 7, but is conveyed a predetermined distance after the trailing edge is detected by the paper feed sensor 35, and then the wide belt 7 is conveyed. 7 is stopped.
As a result, the preceding document P1 is stopped at a predetermined position on the platen 3 (image destination position in the fixed reading mode) with the first surface down.

At this position, the scanner 204
Are scanned, and an image on the first surface of the document P1 is read.

On the other hand, before and after the detection of the trailing edge of the preceding document P1 by the sheet feeding sensor 35, the sheet feeding roller 5 and the separation unit S are driven to separate and feed the succeeding document P2 from the document tray 4 and the second document P2. The skew feeding is performed by the feeding roller 9. Then, the second feeding roller 9, the first reversing roller 17, and the second reversing roller 18 are driven to perform a pre-reversing process for the succeeding document P2 (see FIG. 24E). Note that the subsequent document P2
Indicates that the pre-reversal process is completed while the image of the preceding document P1 is being read, and the leading end of the pre-reversal process is moved to the first reversing roller
(FIG. 24 (f)). The preceding document P1 at this time and the following document P waiting
The paper interval of No. 2 is controlled to be L14.

When the image reading of the preceding original P1 is completed, the first reversing roller 17 and the second reversing roller 18
And the wide belt 7 starts rotating, and the subsequent original P2
Is transported to the platen 3 and stopped at that position (see FIG. 24 (g)). At this time, the rear end of the preceding original P1 has passed through the nip of the manual registration roller 11.

In this state, the scanner 20 of the apparatus main body 1
4 is scanned, and the image on the second surface of the succeeding document P2 is read.

Thereafter, the same operation is continued up to the final document Pn. [4] Manual Feeding Mode Next, the operation in the manual feeding mode will be described with reference to FIGS.

First, the outline of the operation will be described with reference to FIGS. 25 and 26. Here, FIG. 25 is a flowchart showing the outline of the operation in the manual feed mode, and FIG. 26 is a schematic diagram showing the flow of a document when a manual document is conveyed.

When a document is set on the manual document tray 14 (see FIG. 26A), a manual paper feeding process (details will be described later) is started (manualmd1 in FIG. 25), and the set document is moved to a predetermined position on the platen 3. (Fig. 2
6 (b)).

Then, the scanner 204 is scanned and
An original image reading process is performed (see FIG. 25 manual).
lmd2). Then, when the processing is completed, the original is discharged to the paper discharge tray 10 by a paper discharge processing (details will be described later) (see FIG. 25, manualmd3, and FIG. 26C).

Thereafter, the process waits until the trailing edge of the document is detected by the manual registration sensor 34 (manual in FIG. 25).
md4) When the detection is performed, the presence / absence of the next original is detected by the manual insertion original detection sensor 370 (FIG. 25man).
ualmd5). When there is a next original, the above operation is repeated (FIG. 25 manualmd1 to manual).
almd5, see FIG. 26 (d)). If there is no next original, a series of processing is ended.

Next, details of the operation of this mode will be described with reference to FIG.
7 will be described. Here, FIG. 27 is a flowchart showing details of the operation in the manual feed mode.

Usually, the discharge flapper solenoid 109 is turned off, and the discharge flapper 26 and the manual shutter 2 are turned off.
8 is held at the position indicated by the solid line in FIG. Specifically, the paper discharge flapper 26 is held at a position where the tip end is lower than the platen 3, and the manual feed shutter 28 is held in a state of protruding from the manual feed tray 14.

Therefore, when an operator sets a document on the manual document tray 14, the document is placed with its leading end abutting the manual shutter 28.

When the manual document detection sensor 370 detects that a document is set on the manual document tray 14,
The discharge flapper solenoid 109 is turned on (FIG. 27me).
nt1), the paper discharge flapper 26 and the manual feed shutter 28 are moved to the dashed line position in FIG. Also, the discharge motor 104
Is started, the manual feed roller 13 is driven to rotate (mention 2 in FIG. 27), and the document P1 is conveyed in the manual feed path. During this time, the manual registration rollers 11
Has been stopped.

Thereafter, if the leading edge of the original is detected by turning on the manual feed registration sensor 34 (see FIG.
3), the manual feed loop counter, which is counted by the clock signal input from the paper discharge clock, starts counting (mention 4 in FIG. 27), and when the counting is completed, the driving of the paper discharge motor 104 is stopped (FIG. 27m).
ent5, ment6). As a result, the document P1 conveyed by the manual feed roller 13 is stopped in a state where the leading end of the document abuts against the stopped manual registration roller 11 to form a predetermined amount of loop, and the document P1 is conveyed.
Is corrected.

Thereafter, the discharge motor 104 and the belt motor 102 are started (ment7 in FIG. 27), and the manual feed roller 13, the manual registration roller 11, and the wide belt 7 are driven to rotate. As a result, the document P1 is transported from the manual feed path (R) to the document transport path (D).

At the same time as the start of the paper discharge motor 104 and the like, a size check counter which starts counting by a clock signal input from the belt clock is started (ment8 in FIG. 27). Then (Fig. 27men
t10), the counting is stopped. Then, based on the data, a size check process (ment1 in FIG. 27)
1) is performed.

When it is confirmed by turning off the manual feed registration sensor 34 that the rear end of the original has passed through the manual feed roller 13, the discharge motor 104 is turned off and the driving of the manual feed roller 13 is stopped. (Figure 27 men
t12).

On the other hand, simultaneously with the start of the size check counter, the belt registration counter counted by the belt excitation clock is started (FIG. 27me).
nt9). When the counter finishes counting (ment 13 in FIG. 27), the drive of the belt motor 102 (wide belt 7) is stopped (ment 14 in FIG. 27).
The document P1 is stopped at a predetermined position on the platen 3 (a position where the leading edge of the document coincides with the first image destination position R1).

In this state, the scanner 204 scans,
A document reading process is performed.

The discharge flapper solenoid 109 is turned off (ment 15 in FIG. 27), the discharge flapper 26 and the manual shutter 28 are held at the solid line positions in FIG. 2, and the next document can be set.

When the document reading process is completed, the wide belt 7 is driven to rotate in the reverse direction and the paper discharge roller 12 is driven to rotate, and the document P1 is discharged to the paper discharge tray 10. Note that the rotation of the paper discharge roller 12 causes the manual feed roller 13 to rotate, but the second document P2 is prevented from being fed because the leading end thereof is regulated by the manual shutter 28. .

Further, when the trailing end of the document P1 is detected by the manual registration sensor 34, the driving of the manual registration roller 11 is stopped, and the manual flapper 27 and the manual shutter 28 are moved to the solid line positions in FIG.

When the manual paper feed roller 13 is driven, the document P2 is conveyed to the manual paper registration roller 11 and skewed as described above, and then placed on the platen 3.

Next, effects of the present embodiment will be described.

According to the present embodiment, when the reversing process is performed in the double-sided document transport mode, the driving direction of the wide belt 7 is switched while the document is being transported in the reverse feeding path. Therefore, the document is conveyed to the reading position via the reverse feeding path without being stopped, and the upside down is completed. Therefore, the time for performing the document reversal process is reduced, and the productivity is improved.

Further, since the ADF 2 according to the present embodiment is applied to the image forming apparatus G, it is possible to prevent a decrease in image forming speed when performing a document reversal process.

Further, when the switching timing of the driving direction of the wide belt 7 is changed according to the size of the document, the reversing process can be smoothly performed regardless of the size of the document.

In the above-described embodiment, the document size is determined only by the size of the document in the conveyance direction of the document by the document trailing edge detection sensor 41. The document size may be determined using the sensor 44.

[0239]

As described above, according to the present invention,
The document is conveyed to the specified position via the reversing feed path without being stopped, and the reversal is completed.
Therefore, the time for performing the document reversal process is reduced, and the productivity is improved.

When the automatic document feeder according to the present invention is applied to an image forming apparatus, it is possible to prevent a reduction in image forming speed when performing document reversal processing.

In the case where a size detecting means for detecting the size of the document is provided and the document conveying means is driven in the opposite direction at a timing based on the detection result of the size detecting means, the size of the document may be reduced. Regardless, the reversing process can be performed smoothly.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an overall configuration of an image forming apparatus according to the present invention.

FIG. 2 is a detailed sectional view showing the structure of the ADF.

3A and 3B are diagrams illustrating the structure and operation of a paper feed roller and the like disposed at the left end of a document tray, FIG. 3A is a diagram illustrating a maximum rising position of the paper feed roller, and FIG. The figure which shows the maximum descending position of.

FIG. 4 is a plan view showing the structure of a paper feed roller and the like.

FIG. 5 is a diagram showing a document reading position on a platen.

FIG. 6 is a block diagram illustrating a circuit configuration of a control circuit.

FIG. 7 is a flowchart illustrating an outline of the operation of the image forming apparatus.

FIG. 8 is a flowchart illustrating an outline of an operation when a half-size one-sided original is conveyed.

FIG. 9 is a schematic diagram illustrating the flow of a document when a half-size one-sided document is conveyed.

FIG. 10 is a flowchart illustrating details of an operation when a half-size one-sided document is conveyed.

11A is a diagram illustrating a state in which a paper feed roller is in contact with a document, and FIG. 11B is a diagram illustrating a retreat position of the paper feed roller.

FIG. 12 is a flowchart for explaining pickup DOWN processing of a paper feed roller.

FIG. 13 is a flowchart for explaining separation processing.

FIG. 14 is a flowchart for explaining a size check process.

FIG. 15 is a flowchart for explaining an original flow reading process.

FIG. 16 is a flowchart for explaining a pickup UP process of a sheet feeding roller.

FIG. 17 is a flowchart for explaining a sheet discharging process.

FIG. 18 is a flowchart illustrating an outline of an operation when a large-sized one-sided original is conveyed.

FIG. 19 is a schematic diagram illustrating the flow of a document when a large-sized single-sided document is conveyed.

FIG. 20 is a flowchart showing an outline of the operation when a half-size double-sided document is conveyed.

FIG. 21 is a schematic diagram illustrating the flow of a document when a half-size double-sided document is conveyed.

FIG. 22 is a flowchart illustrating details of an operation when a half-size double-sided document is conveyed.

FIG. 23 is a flowchart for explaining a reversing process in the duplex document transport mode.

FIG. 24 is a schematic diagram showing the flow of a document when a large-size double-sided document is conveyed.

FIG. 25 is a flowchart showing an outline of the operation in the manual feed mode.

FIG. 26 is a schematic diagram illustrating the flow of a document when a manual document is conveyed.

FIG. 27 is a flowchart showing details of the operation in the manual feed mode.

[Explanation of symbols]

 2 ADF (automatic document feeder) 3 Platen 7 Wide belt (document conveying means) 17 First reversing roller (reversing feeding means) 18 Second reversing roller (reversing feeding means) 36 Drive roller (document conveying means) 37 turns Roller (document conveying means) 41 Document trailing edge detection sensor (size detecting means) 200 Reader unit (image reading means) G Image forming apparatus P Document E, F, G Reverse feeding path

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Katsuya Yamazaki, Inventor Canon Inc. 3- 30-2 Shimomaruko, Ota-ku, Tokyo (72) Inventor Riki Sato 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Incorporated (72) Inventor Akima Yoshida 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (6)

[Claims] An automatic document feeder for conveying a document to a specified position and reversing the front and back of the document conveyed to the specified position, wherein the document is conveyed to the specified position. Is a document feeder capable of being driven forward and reverse to be carried out from the specified position, a reverse feeding path connected to the specified position, and a document being fed along the reverse feeding path. Reversing feeding means for reversing the front and back of the document, and by driving the document conveying means in a predetermined direction, to convey the document from the specified position to the reversing feeding path, While the document is being conveyed along the reverse feeding path by the feeding means, the document is conveyed to the specified position without stopping by driving the document conveying means in the opposite direction. Especially Automatic document feeder. 2. The image forming apparatus according to claim 1, wherein the document conveying unit includes a wide belt having a width substantially equal to that of the document, a roller for driving the belt,
The automatic document feeder according to claim 1, comprising: 3. The apparatus according to claim 1, further comprising: a size detecting unit configured to detect a size of the document, wherein the document conveying unit is driven in an opposite direction at a timing based on a detection result of the size detecting unit. 2. The automatic document feeder according to 2. 4. An image reading means for reading an image of a document located at a specified position, and an automatic reading means for conveying the document to the specified position and reversing the front and back of the document conveyed to the specified position. A document feeder, wherein the automatic document feeder conveys the document to the specified position or discharges the document from the specified position. Conveying means, a reversing feed path connected to the specified position, and reversing feeding means for reversing the original by conveying the original along the reversing feeding path, and By driving the document conveying means in a predetermined direction, the document is conveyed from the specified position to the reverse feeding path, and the document is conveyed along the reverse feeding path by the reverse feeding means. While An image forming apparatus, comprising: driving the document conveying means in the opposite direction to convey the document to the specified position without stopping. 5. The image reading means has a platen on which a document is placed, and the document conveying means has a width substantially equal to the width of the document and is arranged along the platen. The image forming apparatus according to claim 4, further comprising: a roller that drives a belt. 6. The apparatus according to claim 4, further comprising: a size detecting unit configured to detect a size of the document, wherein the document conveying unit is driven in an opposite direction at a timing based on a detection result of the size detecting unit. 6. The image forming apparatus according to 5.