JP2003341943A - Automatic document feeder and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To handle a document of a short carrying direction length, to shorten reading time and improve visibility of the document after ejected, in an automatic document feeder. <P>SOLUTION: This feeder is provided with each of a reversing means 6 and an ejection means 4. The reversing means 6 and the ejection means 4 are arranged so that a horizontal distance from a document reading position R to the ejection means 4 may be longer than a horizontal distance from the document reading position R to the reversing means 6. Since the reversing means 6 can be arranged closely to the document reading position R, also the document of the short carrying direction length can be handled and reading time can be shortened by shorting a carrier path. Since the ejection means 4 can be arranged to be away from the reading position R, visibility of the document D discharged to a discharging tray 5 by the ejection means 4 can be improved. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic document feeder for automatically conveying a document in a copying machine, a printer, a facsimile, etc., and an image forming apparatus equipped with the same.

[0002]

2. Description of the Related Art As an automatic document feeder used in an image forming apparatus such as a copying machine or a printer, there is known an automatic document feeder capable of automatically reading both sides of a document.

As an example of such an automatic document feeder,
JP-A-7-175279, JP-A-9-10611
No. 6, which is disclosed in FIG.
Is schematically shown in.

Among them, the one shown in FIG. 6 is one in which the stacking tray 101, the stacking tray 101, and the stacking tray 101 are arranged in order along the conveying direction of the document D (direction of arrow a).
Pickup roller 102, paper feed roller 103, conveyance roller pair 104, conveyance drum 105, and conveyance rollers 106, 107, 108 that are in contact therewith, discharge reversal roller pair 1
10 and a discharge tray 111. A document reading position R is set between the transport rollers 107 and 108. Here, the upper surface of the document D placed on the stacking tray 101 is referred to as A surface, and the lower surface thereof is referred to as B surface.

When only the A side of the original is read, the original D supplied from the stack tray 101 and having the A side read
Are immediately discharged onto the discharge tray 111 by the pair of discharge reverse rollers 110. That is, the plurality of documents D set on the stacking tray 101 are not picked up by the pickup roller 10
2, 1 by the feeding roller 103 and the conveying roller pair 104
Sheets are fed and conveyed one by one. Furthermore, the transport drum 10
5. The surface A is read at the document reading position R while being transported by the transport rollers 106, 107 and 108. The document D after the A side is read is output by the discharge reverse roller 110.
The sheet is conveyed in the direction of the arrow a by the rotation of the arrow direction and is discharged onto the discharge tray 111 with the surface A facing downward.

On the other hand, when both the A-side and the B-side are read, the document D whose A-side has been read in the same manner as described above is rotated by the pair of discharge reversing rollers 110 in the direction of the arrow to cause the arrow a. When the rear end portion of the discharge reverse roller 110 is conveyed in the direction
Is reversed. The original document D is thus conveyed in the direction of the arrow b, and is conveyed by the conveying drum 105 and the conveying rollers 106, 107, 108 in a state of being turned upside down.
At the document reading position R, the B side is read this time. The document D after the side B is read is idly rotated, turned upside down, and then discharged onto the discharge tray 111. That is, the document D after the side B is read is fed by the discharge reversing roller pair 11
0 is rotated in the direction of the arrow a, and when the rear end portion reaches the pair of discharge reversing rollers 110, the discharge reversing rollers 110 are reversed so that the arrow b
Is conveyed in the direction. Then, the sheet is conveyed by the conveying drum 105 and the conveying rollers 106, 107, 108, and is discharged onto the discharge tray 111 without being read. At this time, the document D is ejected with the side A facing downward.

Next, FIG. 7 will be described. The automatic document feeder shown in FIG. 7 is basically the same as that shown in FIG. 6 except for the structure for reversing the document D.
Differences from the automatic document feeder of FIG. 6 will be mainly described.

The automatic document feeder shown in FIG. 7 has a driving roller 112, driven rollers 113 and 114, and a switching claw 11.
5, a reverse roller pair 116, and an intermediate tray 117. In the apparatus shown in the figure, the driving roller 112 and the lower driven roller 113 form a discharge roller pair.

In this apparatus, when only the side A of the document D is read, the switching claw 115 is arranged at the position shown by the dotted line and the drive roller 112 is rotated in the direction of the arrow so that the document D after the side A is read. , And is discharged onto the discharge tray 111.

On the other hand, when both the A side and the B side can be read, the document D after the A side is read has the switching claw 1
15 is arranged in the solid line position, and the drive roller 112 and the reversing roller pair 116 rotate in the direction of the arrow to be guided onto the intermediate tray 117. When the rear end of the document D reaches the reversing roller pair 116, the reversing roller pair 116 is reversed, whereby the document D is conveyed in the direction of the arrow b, and the document D is reversed in the document reading position R. Next, side B is read. The document D after the side B is read is idled and turned upside down, and then the discharge tray 11
1 discharged on top. That is, the document D after the side B is read
In the same manner as described above, the switching claw 115 is arranged at the solid line position, and the drive roller 112 and the reversing roller pair 116 rotate in the direction of the arrow to be guided onto the intermediate tray 117. When the trailing end of the original D reaches the pair of reversing rollers 116, the pair of reversing rollers 116 is reversed, whereby it is conveyed in the direction of arrow b, and the switching claw 115 is moved to the dotted line position without being read. When the drive roller 112 is disposed and rotates in the direction of the arrow, it is discharged onto the discharge tray 111 with the surface A facing downward.

[0011]

By the way, in the above-described automatic document feeder capable of automatically reading both sides (A side and B side) of the document D, the pair of reversing rollers is generally The distance from the document reading position R is short,
Further, it is preferable that the discharge roller pair has a long distance from the document reading position R.

Because, when the reversing roller pair is far from the document reading position R, the distance from the reversing roller pair to the conveying member (conveying roller 106 or conveying roller 108 in the example of FIG. 6) adjacent thereto is small. This is because it becomes long and it becomes impossible to convey a document having a size smaller than this distance (short in the conveyance direction). Further, in such a case, the document conveyance path becomes long, and the time required to read the document (particularly the time when the B-side is read and when idling) is increased. If the distance between the reversing roller and the conveying member adjacent to the reversing roller is long, by adding another conveying member in the middle, it is possible to cope with a document having a small size (the length in the conveying direction is short). However, the configuration becomes complicated accordingly.

On the other hand, the pair of discharge rollers are set at the document reading position R.
When the original D is read, the discharge position of the original D after reading is correspondingly to the back side (the left side in the examples of FIGS. 6 and 7), and the original D to be discharged is obstructed by the stacking tray 101 or the intermediate tray 117. This is because the visibility with respect to is reduced. Note that, in general, the operator's viewpoint is located above the stacking tray. Therefore, in order for the operator to confirm the document discharged onto the discharge tray 111, the space between the stack tray 101 and the discharge tray 111 is looked into from the diagonally upper side of the stack tray 101.

As described above, the reversing roller pair is close to the document reading position R, and the discharge roller pair is near the document reading position R.
However, in the configuration shown in FIG. 6, since the pair of reversing rollers and the pair of discharging rollers are combined to form the pair of discharging and reversing rollers 110, the above-described preferable configuration cannot be satisfied. . That is, when the discharge reversing roller pair 110 is brought close to the document reading position R, the document discharging position is displaced to the inner side of the stacking tray 101 (leftward direction in FIG. 6), and the document D discharged onto the discharging tray 111. Is less visible. On the other hand, if the discharge reversing roller pair 110 is separated from the document reading position R, the visibility of the document D discharged onto the discharge tray 111 can be improved, but from the document reading position R to the discharge reversing roller pair 110. However, there is a problem in that the time required to read the document becomes longer because the distance is longer.

In the structure shown in FIG. 7, the reversing roller pair 116 is far from the document reading position R, and the discharge roller pair (driving roller 112 and driven roller 113) is close to the document reading position R. Therefore, the automatic document feeder shown in FIG. 7 takes a long time to read a document when reading a double-sided document, and also the discharge tray 1
It becomes difficult for the operator to confirm the document discharged onto the sheet 11.

Therefore, according to the present invention, a pair of reversing rollers and a pair of discharging rollers are separately configured, and further, by appropriately setting the positional relationship between them, a short original can be read, and a double-sided original reading time can be obtained. The purpose is to shorten the time and improve the visibility of the document at the time of ejection.

[0017]

According to a first aspect of the present invention, there is provided a supplying means for supplying a document on a stacking portion to a document reading position, a discharging means for discharging a read document to a discharging section, and a read document. An automatic document feeder including a reversing unit that reverses the front and back and re-supplies to the document reading position, the reversing unit is disposed below the stacking unit, and the discharging unit is disposed below the reversing unit. It relates to the device. The inverting means and the discharging means are arranged such that a horizontal distance from the original reading position to the discharging means is longer than a horizontal distance from the original reading position to the inverting means. There is.

According to a second aspect of the present invention, in the automatic document feeder according to the first aspect, the reversing means forms a reversing nip that abuts each other substantially vertically and forms a reversing nip for nipping and conveying the document. It is characterized by having a roller and a reverse lower roller.

According to a third aspect of the present invention, in the automatic document feeder according to the first or second aspect, the discharge means are in contact with each other in a substantially vertical direction to form a discharge nip for sandwiching and conveying the document. It has a discharge upper roller and a discharge lower roller.

According to a fourth aspect of the invention, in the automatic document feeder according to the third aspect, the reversing nip is located above the discharging nip.

According to a fifth aspect of the invention, in the automatic document feeder according to the fourth aspect, a switching member is provided which has a reversing position for guiding the read document to the reversing nip portion and a discharging position for guiding the reversing nip portion. It is characterized by having.

According to a sixth aspect of the invention, in the automatic document feeder according to the fifth aspect, the end side of the document, which is held in the reversing nip, on the side far from the document reading position is supported from below. It is characterized by having an intermediate support member.

According to a seventh aspect of the present invention, the original reading means for reading the original at the original reading position, the automatic original feeding means for supplying the original to the original reading position and unloading the read original, and the original reading means. An image including an image forming unit that forms an image on a recording material based on the read image information, and a recording material feeding / conveying unit that supplies the recording material to the image forming unit and carries out the recording material after the image formation. The present invention relates to a forming device. The automatic document feeder is the automatic document feeder according to any one of claims 1 to 6.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

(Automatic Document Feeding Device) FIG. 1 is a vertical sectional view showing a main part of the automatic document feeding device 1 according to the present embodiment. In the following description, the left side in the figure is the front end side, and the right side in the figure is the rear end side.

As shown in the figure, the automatic document feeder 1
Is a stacking tray 2 as a stacking unit on which a plurality of documents D are stacked, a supply unit 3 that conveys the document D on the stacking tray 2 to a document reading position R, and a discharge unit that discharges the document D after reading. 4, a discharge tray 5 as a discharge unit that supports the document D discharged from the discharge unit 4 from below, and a reversing unit 6 that reverses the document D after reading and supplies the document D again to the reading position. .

Of these, the stacking tray 2 is provided above the automatic document feeder 1. The stacking tray 2 is formed in a substantially flat shape, and the front end side is gently inclined downward. A separation wall 7 formed of an inclined surface that rises forward is formed at the most front end side of the stacking tray 2. Loading tray 2
The document D stacked on the upper end of the document D comes into contact with the separation wall 7, and when the paper is fed, which will be described later, the front end of the document D is rubbed against the separation wall 7 and overcomes the separation, so that the separation is properly performed. ing. Documents D stacked on the stacking tray 2
Are loaded so that the first surface (front surface), surface A, faces upward, and the second surface (back surface), surface B, faces downward.

In the vicinity of the leading end of the stacking tray 2, a set switch 8 which acts as a presence / absence sensor for the document D is arranged. The set switch 8 is an arm-shaped member having a swing center 8a above the stacking tray 2, and is supported so as to swing with a small force with respect to the swing center 8a. When there is even one document D on the stacking tray 2, the set switch 8 takes a retracted position (not shown) in which the leading end 8b is lightly placed on the document D. On the other hand, when the document D on the stacking tray 2 is exhausted, the leading end 8b enters a through hole (not shown) formed in the stacking tray 2 and takes the operating position shown by the solid line in FIG. At this time, for example, the front end 8b blocks the optical path of the light transmissive optical sensor, so that it is detected that the document D has disappeared.

The supply means 3 is a pickup roller (forward feed roller) arranged near the set switch 8 described above.
10, a paper feed roller 11 arranged in front of the paper feed roller 11 (on the left side in FIG. 1), a large-diameter transport drum 12 disposed obliquely below the paper feed roller 11, and a substantially front side of the transport drum 12. The pre-reading roller 13 that is in contact with the conveying drum 1
2 has a post-reading roller 14 that is in contact with the rear (right side in FIG. 1) from diagonally below.

Of these, the pickup roller 10 is connected to a paper feed motor 16 via a paper feed clutch 15. The pickup roller 10 is the paper feed motor 1 described above.
6. When rotated clockwise by the paper feed clutch 15, the paper feed position shown by the dotted line from the home position shown by the solid line in FIG. 1, that is, the position where it comes into light contact with the A surface of the uppermost document D. On the other hand, when the paper feed motor 16 rotates in the opposite direction while it moves (swings about the CL point), it returns to the home position. As the paper feed motor 16, a forward / reverse rotatable stepping motor that rotates by a rotation angle (rotation speed) proportional to the number of pulses can be used.

The paper feed roller 11 is also connected to the paper feed motor 16 via the paper feed clutch 15 like the pickup roller 10 described above. The paper feed roller 11 is in contact with the separation pad 17 from above. The paper feed roller 11 is
It is driven to rotate clockwise by the paper feed motor 16 and the paper feed clutch 15, and feeds the originals D delivered from the pickup roller 10 one by one toward the downstream side by a frictional force. The separation pad 17 prevents the second and subsequent documents D from being double-fed.

The pickup roller 10 and the feeding roller 11 described above rotate in the clockwise direction in reverse with the counterclockwise rotation of the paper feeding motor 16, and are one-way clutches when the paper feeding motor 16 rotates in the clockwise direction. The rotation of the paper feed clutch 15 is stopped by the action of the paper feed clutch 15.

The transport drum 12 is disposed immediately above the document reading position R, and is connected to a transport motor 20 via a transport clutch 18. This transport motor 20
Is also connected to a discharging means 4 and a reversing means 6 which will be described later, via a transport clutch 18. As the carry motor 20, a stepping motor that can rotate in the forward and reverse directions is used, as in the paper feed motor 16 described above. This transport drum 12
Has a one-way clutch (not shown) interposed between the shaft and the shaft so that it does not rotate clockwise even when the carry motor 20 rotates clockwise. That is, the transport drum 12 also rotates counterclockwise as the transport motor 20 rotates counterclockwise, and maintains a stopped state when the transport motor 20 rotates clockwise.

The pre-reading roller 13 is brought into contact with the surface of the above-described conveying drum 12 and is placed between the pre-reading roller 13 and the conveying drum 12 with the first roller
Transport nip N1 is formed. Pre-reading roller 1
3 is driven to rotate in a clockwise direction by the counterclockwise rotation of the transport drum 12, whereby the document D is nipped and transported by the transport nip N1.

A timing switch 21 is provided immediately upstream of the pre-reading roller 13 (upstream in the document transport direction; the same applies hereinafter). The timing switch 21 retracts to the retracted position indicated by the dotted line in FIG. 1 when the leading edge of the document D comes into contact, and holds this retracted position until the document D has finished passing. When the trailing edge of the document D has finished passing, it returns to the operating position indicated by the solid line in FIG. Timing switch 21
Is arranged to block the optical path of, for example, a light transmission type optical sensor (not shown) when it is arranged at the retracted position. As a result, conversely, it is detected that the leading edge of the document D has reached the timing sensor 21. Further, by restarting the blocked optical path, it is detected that the trailing edge of the document D has finished passing through the timing sensor 21. The leading edge detection or the trailing edge detection of the document D by the timing switch 21 is adopted as a reference for the operation timing of each roller and the switching member (described later).

The post-reading roller 14 has the same structure as the above-mentioned pre-reading roller 13. That is, the post-reading roller 14 is in contact with the surface of the transport drum 12 to form a second transport nip N2 with the transport drum 12. The post-reading roller 14 is driven to rotate clockwise by the counterclockwise rotation of the conveying drum 12, and thereby nips and conveys the document D at the conveying nip N2.

Below the above-mentioned conveying drum 12, a slit glass 22 for forming the document reading position R is arranged. A document guide 23 is arranged above the slit glass 22. The original document guide 23 is an original document D formed around the conveying drum 12.
In order to narrow the conveyance path of the document in the vicinity of the document reading position R, it is arranged to face the slit glass 22 with a minute gap.

A switching member 24 is disposed downstream of the post-reading roller 14 described above. The switching member 24 is
It is swingably supported with the swing center 24a on the rear end side as a reference. The switching member 24 is a reverse branch solenoid 25.
Is connected, and the reverse branch solenoid 25 is turned on.
Thus, it is arranged at the inversion position shown by the dotted line in FIG. 1, and when it is turned off, it is arranged at the discharge position shown by the solid line in FIG. The document D after being read is guided to the discharging means 4 when the switching member 24 is arranged at the discharging position, and is guided to the inverting means 6 when being arranged at the reversing position.

Behind the switching member 24 (right side in FIG. 1),
The inverting means 6 is arranged, and the discharging means 4 is arranged on the right side of the inverting means 6 in FIG. Of these, the reversing means 6
Has a reversing upper roller 26 and a reversing lower roller 27 that form a reversing nip N3 that is in contact with each other from above and below and holds and conveys the document D. Among them, the reversing upper roller 26 is provided with the transport motor 2 via the transport clutch 18 described above.
It is linked to 0. The upper reversing roller 26 also rotates clockwise and counterclockwise as the carry motor 20 rotates clockwise and counterclockwise. On the other hand, the reversing lower roller 27 is a driven roller, and can come into contact with and separate from the reversing upper roller 26 from below. When the suction side of the reversing pressure solenoid 28 is turned on, the reversing lower roller 27 takes a separating position to open the reversing nip N3 as shown by the dotted line in FIG. 1, and the reversing pressure solenoid 28 is turned off on the returning side. As a result, as shown by the solid line in FIG. 1, the contact position that forms the reversal nip N3 is taken.

The discharging means 4 has a discharging upper roller 30 and a discharging lower roller 31 which are in contact with each other in a substantially vertical direction and form a discharging nip N4 for nipping and conveying the document D. Of these, the latter discharge lower roller 31 is connected to the transport motor 20 via the above-described transport clutch 18, like the above-described reverse upper roller 26. This discharge lower roller 31
Is rotated counterclockwise and clockwise in accordance with the clockwise and counterclockwise rotation of the carry motor 20. On the other hand, the discharge upper roller 30 is a driven roller, and as the discharge lower roller 31 is driven and rotated,
Followed rotation.

The discharge tray 5 is arranged behind the discharge means 4 (downstream side in the document conveying direction) and below the discharge means 4. In the discharge tray 5, the documents D sequentially discharged from the discharge means 4 are sequentially stacked on the discharge tray 5 to be in a stacked state. The discharge tray 5
Whether the original D discharged on the upper side is read on only one side (A side) or both sides (A side and B side)
As will be described later, the sheet is discharged with the side A facing downward.

Behind the reversing means 6 (downstream side in the document conveying direction)
Is provided with an intermediate tray 32 as an intermediate support member. The intermediate tray 32 is arranged so as to cover above the discharge tray 5 described above, the upper surface 32a on the tip side is substantially at the same height as the upper end of the discharge upper roller 30, and the lower surface 32b on the tip side is described above. It is set so as to be located slightly above the discharge nip N4 of the discharge means 4. Since the height of the upper surface 32a and the lower surface 32b of the intermediate tray 32 is set as described above, the document reading position R of the document D conveyed from the reversing unit 6 when the document D is reversed, which will be described later. The end side on the side farther from is favorably supported from below, and does not interfere with the document D discharged from the discharging unit 4 when the document D described later is discharged.

Here, the positional relationship between the discharging means 4 and the reversing means 6 in the present embodiment will be described in detail.

The inverting means 6 and the discharging means 4 are arranged so that the horizontal distance from the document reading position R is longer in the discharging means 6 than in the inverting means 6. Thereby, the reversing nip N3 between the reversing upper roller 26 and the reversing lower roller 27 of the reversing means 6, the first conveying nip N1 between the conveying drum 12 and the pre-reading roller 13, the conveying drum 12 and the reading. With respect to the second transport nip N2 between the rear roller 14 and the second transport nip N2, the distance from the reversal nip N3 to the first transport nip N1 and the second transport nip N2 (distance along the document transport direction. The same applies hereinafter). Can be shortened. That is, at the time of reversing the document D, it is necessary that the document D is sandwiched by at least one of the reversing nip N3 and the first transport nip N1, and at least one of the reversing nip N3 and the second transport nip N2. However, since these distances can be shortened, the document D having a short length in the transport direction can also be used. Also, by reducing these distances, the document D
It is possible to shorten the transport distance of the document D, particularly the transport distance of the document D at the time of reversal and idle rotation, and thereby shorten the time required to read the document. In this case, the greater the number of documents, the greater the cumulative effect of time reduction. On the other hand, since the distance from the discharge nip N4 formed between the discharge upper roller 30 and the discharge lower roller 31 in the discharge means 4 to the second transport nip N2 can be made long, the discharge means 4 and the discharge tray 5 are provided. Can be disposed on the rear end side (position far from the document reading position R to the right side in FIG. 1). Therefore, the visibility of the document D discharged from the discharging unit 4 can be improved.

The height of the reversing nip N3 is set higher than the height of the carry-out nip N4, and
The upper height of the rear end side of the switching member 24 at the discharge position and the reverse position, the height of the reverse nip N3, the height of the uppermost portion of the discharge upper roller 30, and the front end side of the intermediate tray 32. Since the height of the upper surface 32a of the document D substantially coincides with the height of the upper surface 32a, it is possible to smoothly perform the inversion operation and the idling operation of the document D described later.

Further, the height of the lower side of the rear end side of the switching member 24 when the switching member 24 is at the discharging position and the height of the lowest portion of the reverse lower roller when the contact position is taken. Since the height is substantially the same as the height of the discharge nip N4, the discharge operation of the document D described later can be smoothly performed.

In the present embodiment, the length of the document D in the carrying direction is set to be at least longer than the distance from the reversing nip N3 to the first carrying nip N1. It is possible to set the position of the discharge nip N4 further rearward by making the distance from the discharge nip N4 to the discharge nip N4 as long as the distance between the reversing nip N3 and the first transport nip N1. In order to transmit power from the reversing upper roller 26 to the discharging lower roller 31, for example, the diameter of the gear becomes large,
Since the number of gears increases, in order to prevent these, the discharging means 4 is arranged immediately behind the reversing means 6 so as to be adjacent thereto.

The operation of the entire automatic document feeder 1 having the above-mentioned configuration is controlled by the control means (not shown).

Next, the operation of the automatic document feeder 1 having the above structure will be described with reference to the flow charts shown in FIGS.

First, referring to FIG. 2, one side (A
The case of reading only the surface will be described. When only one side (A side) of a plurality of documents D is continuously read, the document interval between the preceding document D and the following document D is made constant in order to improve work efficiency. The document D is continuously read so as to be read.

Further, for convenience of explanation, in the conveyance path of the document D, the section from the feeding roller 11 to the first conveyance nip N1 is referred to as "supply path P1", and the first conveyance nip N1 to the second conveyance nip N2. Is the "reading path P2", and the portion from the second transport nip N2 to the discharging nip N4 is the "discharging path P2".
3 ", the second conveyance nip N2 to the reversal nip N3 is referred to as" pre-reversal path P4 ", and the reversal nip N3 to the first conveyance nip N1 is referred to as" post-reversal path P5 ".

Similarly, for convenience of description, the description of the operation of the paper feed motor 16, the paper feed clutch 15, the carry motor 20, and the carry clutch 18 will be omitted as appropriate, and the operation of each roller rotationally driven by these will be mainly described. . Further, the actual control is performed by counting the number of pulses at the start of rotation of the sheet feeding motor 16 and the conveyance motor 20, at the end of rotation, and when the timing switch 21 is turned on and off. In the description, the detailed description will be omitted.

The outline of the flow of the document D when reading one side (A side) is as follows. The original document D set on the stacking tray 2 is supplied to the supply path P1 by the feeding roller 11 and the like and is read at the original document reading position R while being conveyed in the reading path P2 by the conveying drum 12 and the like, and then the discharge path. The paper is conveyed through P3 and is discharged onto the discharge tray 5 by the discharging means 4. less than,
This single-sided document reading operation will be described in detail.

When the document D is placed on the stacking tray 2 with its A-side facing upward, the set switch 8 retracts upward and is turned on.

Further, the reversing branch solenoid 25 is turned off and the switching member 24 is arranged at the discharge position shown by the solid line in FIG.

Further, the reversing pressure solenoid 28 is turned on to the pressure side, the reversing lower roller 27 is arranged at the contact position shown by the solid line in FIG. 1, and the reversing nip N3 is formed between the reversing upper roller 26 and the reversing upper roller 26. Is forming.

When the automatic document feeder 1 receives the start signal (step S1; hereinafter referred to as "S1"), the sheet feeding motor 16 rotates counterclockwise (hereinafter referred to as "counterclockwise rotation"). Then, the pickup roller 10 and the feeding roller 11 start clockwise rotation (hereinafter referred to as “right rotation”) (S2), and the pickup roller 10 moves from the home position (solid line in FIG. 1) to the paper feeding position ( 1) and comes in contact with the uppermost document D on the stacking tray 2, and the pickup roller 10 and the feeding roller 1
By rotating 1 to the right. Feeding the original D to the feed path P1 (1
Next paper feeding) is started.

The timing switch 21 is turned on (retracted to the position of the dotted line) within a predetermined time after the rotation of the paper feed motor 16 is started.
If not (No in S3), retry control (S4)
to go into. In this retry control, the paper feed motor 16 is temporarily stopped and the pickup roller 10 and the feeding roller 11 are
Is temporarily stopped (S5), and then the paper feed motor 16 is restarted to pick up the pickup roller 10 and the feeding roller 11.
Is again rotated clockwise (S6), and it is checked whether the timing switching S4 is turned on within a predetermined time (S3). By performing such retry control, it is possible to increase the conveyance force of the pickup roller 10 and the feeding roller 11 with respect to the document D, and it is possible to eliminate a slight conveyance defect. This retry control is performed up to 5 times, and if the timing switch does not turn on after 5 times (S3
No, No in S4), it is determined that a jam (paper jam) has occurred (S7).

On the other hand, if the timing switch 21 is turned on within a predetermined time (Yes in S3) before the retry control of five times is completed, if the carry motor 20 is not off, that is, the left side of the carry motor 20. When the conveyance drum 12 is rotating counterclockwise due to the rotation and the document D is being read (No in S8), the paper feed motor 16 is stopped and the pickup roller 10 and the feeding roller 11 are stopped (S8).
9) Wait for the conveyance motor 20 to stop and the conveyance drum 12 to stop. The transport motor 20 stops when the trailing edge of the document D passes through the document reading position R.

When the transport drum 12 is stopped (Yes in S8)
s), the paper feed motor 16 is rotated counterclockwise, and the pickup roller 10 and the feed roller 11 are rotated clockwise (S1).
0). As a result, the rear end side of the document D is conveyed with the leading end thereof being in contact with the first conveying nip N1 between the stopped conveying drum 12 and the pre-reading roller 13,
A tip can be formed by forming a bend. After the leading edge registration is completed, the paper feed motor 16 is stopped to stop the pickup roller 10 and the feeding roller 11 (S
11). As a result, the primary paper feeding for feeding the document D to the first feeding nip N1 is completed.

Then, the secondary paper feeding is started. The carry motor 20 is rotated counterclockwise to rotate the carry drum 12 counterclockwise (S12). As a result, the document D is pinched by the first transport nip N1 and the reading path P2.
Is fed to the document reading position R, and the reading of side A is started.

As the reading progresses, the trailing edge of the document D passes through the timing switch 21 and the timing switch 21 is turned off (S13).

At this time, when the set switch 8 is ON (Yes in S14), since the next original D is on the stacking tray 2, the feeding of the original D is started. When the reading of the document D is completed, the paper feed motor 16 is rotated counterclockwise, and the pickup roller 10 and the feeding roller 11 are rotated clockwise (S15). Further, when the trailing edge of the document D passes through the document reading position R, the transport motor 12 is stopped and the transport drum 12 is stopped (S16). Then, the process proceeds to step S2 described above, and the primary feeding of the next document D is started.

On the other hand, in step S14, when the set switch 8 is OFF (No in S14), since the original document D currently being conveyed is the final original document, the paper feed motor 16 is stopped and the pickup roller 10 and the feeding roller 16 are fed. The rotation of the roller 11 is stopped (S17). At this time, the pickup roller 10 returns to the home position shown by the solid line position in FIG. 1 by the spring force of the spring clutch. Then, when the trailing edge of the document D passes through the discharge nip N3, the conveyance motor 20
To stop the lower discharge roller 31 (S1
8). As a result, the reading of one side (A side) of the document D is completed.

At the time of reading the above-mentioned original, the original D is nipped and conveyed by the first and second conveyance nips N1 and N2 as the conveyance drum 12 rotates counterclockwise. At this time, if the rotation speed of the feeding roller 11 side is slower than the rotation speed of the transport drum 12 side, the portion of the document D being read located on the trailing edge side supply path P1 is fed with the pre-reading roller 13. It is in a state of being pulled with the feed roller 11. Therefore,
A shock may occur when the trailing edge of the document D passes through the feeding roller 11, a load fluctuation may occur on the transport drum 1, and the transport speed of the document D may be subtly changed to cause a reading failure.

In order to prevent such a reading failure,
In the present embodiment, the rotation speed of the feeding roller 11 is increased immediately before the trailing edge of the document D being read passes through the feeding roller 11. The rotation speed of the feeding roller 11 at this time is, for example, about 1.5% of the feeding speed of the document D by the feeding drum 12,
It is set so that the conveyance speed of the rear end portion due to is high. As a result, slack is formed on the rear end side of the document D in the stretched state, and the above-described shock can be prevented from occurring.

Next, referring to the flow charts shown in FIGS. 3 and 4, the case where both sides (A side and B side) of the document D are read will be described.

The outline of the flow of the document D when reading both sides (A side and B side) is as follows. Loading tray 2
The original D set on the upper side is supplied to the supply path P1 by the feeding roller 11 and the like, and is conveyed in the reading path P2 by the conveying drum 12 and the like, and the original reading position R is obtained.
At A, side A is read. Then, the pre-reversal path P
4. After reversing, the front and back are reversed by the path P5. And
The document D is conveyed from the post-reversal path P5 through the reading path P2, the side B is read at the document reading position R, and then the front and back paths P4 and P5 are reversed again. Then, the original D whose display has been inverted again is conveyed from the post-reversal path P5 to the reading path P2, is conveyed without being read at the original reading position R in the reading path P2, and is then conveyed in the discharge path P3. Then, it is discharged onto the discharge tray 5 by the discharging means 4.

Hereinafter, the case of reading this double-sided original will be described in detail. Note that steps S1 to S11 shown in FIG. 3 are the same as those in the case of single-sided reading shown in FIG. 2 described above, and therefore description thereof will be omitted.

As shown in FIG. 3, in the case of reading both sides of the document D, the reversal is started after the primary sheet feeding is completed in step S11.

The carrying motor 20 is rotated counterclockwise, and the carrying drum 12 and the reversing upper roller 26 are rotated counterclockwise (S21).
Before the leading edge of the document D reaches the switching member 24, the reversing branch solenoid 25 is turned on and the switching member 24 is arranged at the reversing position (dotted line in FIG. 1) (S22). As a result, the discharge path P3 is closed and the reversal path P4 is opened. Then, the document D is guided by the switching member 24 and conveyed in the reversing path P4 toward the reversing means 4. Further, the document D is nipped and conveyed by the reversing nip N3 by the counterclockwise rotation of the reversing upper roller 26, and the leading end side thereof moves backward (to the right in FIG. 1) following the upper surface of the intermediate tray 32. When the trailing edge of the document D passes through the timing switch 21 and the timing switch 21 is turned off (S2
3) When the rear end of the document D reaches the rear end of the switching member 24, the reversing branch solenoid 25 is turned off, and the switching member 24 is arranged at the discharge position shown by the solid line in FIG. 1 (S).
24). As a result, the pre-reversal path P4 is closed and the post-reversal path P5 is communicated. Further, at almost the same time, the carry motor 20 is rotated to the right, whereby the upper reversing roller 26 is rotated to the right. As a result, the document D is sent out substantially forward (leftward in FIG. 1) in the reversing path P5, with the trailing end being the leading end.
3 is conveyed. At this time, the transport drum 1
No. 2 is in a stopped state due to the action of the one-way clutch described above. Then, after the timing switch 21 is turned on by the leading edge of the original document D (S26), the leading edge of the original document D contacts the first transport nip N1, and the leading edge registration of the original document D is performed. After that, the conveyance motor 20 is stopped, so that the upper reversing roller 26 is stopped (S27), thereby ending the reversing operation of the document D.

After the completion of this reversing operation, the secondary paper feeding is started. By the left rotation of the carry motor 20, the carry drum 12,
The reversing upper roller 26 is rotated counterclockwise (S28). Then, almost at the same time as the start of the secondary sheet feeding, the reversing pressure solenoid 28 is turned on to the suction side, the reversing lower roller 27 is arranged at the separated position (dotted line in FIG. 1), and the reversing nip N3 is released. (S29). As a result, the document D is conveyed in the reading path P2, and the B side is read at the document reading position R. Next, the leading edge of the document D is changed to the switching member 2.
Before reaching 4, the reversing branch solenoid 25 is turned on and the switching member 24 is arranged at the reversing position (dotted line in FIG. 1) (S30).

After the trailing edge of the document D turns off the timing switch 21, the reverse pressure solenoid 28 is turned on to the return side.
Then, the reversal lower roller 27 is arranged at the contact position (solid line in FIG. 1), and the reversal nip N3 is formed (S31).
As a result, the document D with the A side facing up is nipped and conveyed onto the intermediate tray 32 by the reversal nip N3, and the rear end portion (the left end in FIG. 1) of the document D is nipped by the reversal nip N3. Becomes

After that, Repeat 1 (S32) of FIG.
Is repeated. As a result, the document D is turned over again (the same as when it was first fed to the feed path P1 by the feeding roller 11), and its leading end is in contact with the first transport nip N1. Will be stopped at.

After that, when the carry motor 20 rotates counterclockwise and the carry drum 12 is rotated counterclockwise (S33), the document D
Are nipped and conveyed by the first conveyance nip N1. At this time, the reverse pressure solenoid 28 is turned on to the suction side,
The reverse lower roller 27 is arranged at the separated position (S34), and the reverse nip N3 is released so that the resistance of the reverse nip N3 does not act on the document D. After that, when the timing switch 21 is turned off by the rear end of the document D (S35), the reversing pressure solenoid 28 is turned on to the return side, and the reversing lower roller 27 is placed at the contact position (S36). N3 is formed. As a result, the discharge path P3 is opened. The original D is the first
Although the document is fed to the reading path P2 by the transport nip N1, the document is not read, the document is fed to the discharge path P3 by the second transport nip N2, and then discharged onto the discharge tray 5 by the discharge means 4. .

When the reverse pressure solenoid 28 is turned on to the return side (S36), the set switch 8 is turned off.
In the case of N (Yes in S37), since the next document D is on the stacking tray 2, the feeding of this document D is started.
When the reading of the document D is completed, the paper feed motor 16 is rotated counterclockwise to pick up the pickup roller 10 and the feeding roller 1.
1 rotates right (S38). Further, when the trailing edge of the document D passes through the document reading position R, the transport motor 12 is stopped and the transport drum 12 is stopped (S39). After that, the process proceeds to step S2 of FIG. 3, and the primary feeding of the next original D is started.

On the other hand, in step S37, when the set switch 8 is OFF (No in S37), since the original document D currently being conveyed is the final original document, this original document D is ejected by rotating the ejection lower roller 31 to the right, When the trailing edge of the document D passes through the discharge nip N3, the conveyance motor 20 is stopped and the discharge lower roller 31 is stopped (S40).

After that, the paper feed motor 16 is stopped, and the pickup roller 10 and the feeding roller 11 are stopped (S41). As a result, the reading of both sides of the document D is completed.

(Image Forming Apparatus) FIG. 5 is a schematic view showing an example of an image forming apparatus 50 equipped with the automatic document feeder 1 according to the present invention.

The image forming apparatus 50 shown in FIG. 5 includes a document reading unit 51, an automatic document feeding unit, an image forming unit 52, a recording material feeding / conveying device 53, and a recording material reversing unit 54.
It has and.

As the automatic document feeding means, the automatic document feeding device 1 according to the first embodiment described above can be used. As the document reading unit 51, a known optical document reading device can be used. The document reading unit 51 sequentially reads the documents conveyed to the document reading position R by the automatic document feeder 1. The image forming unit 52 forms a toner image on the recording material P such as paper based on the image information read by the above-described document reading device 51. The recording material feeding / conveying device 53 is
The recording material P is supplied to the image forming section 52, and the recording material P after the image formation is carried out from the image forming section 52. The recording material reversing means 54 reverses the recording material P having an image formed on one surface thereof, and supplies the image to the image forming section 52 again. By providing the recording material inverting means 54,
For example, images on both sides of the original can be automatically formed on both sides of the recording material P as they are.

The above-mentioned image forming section 52 may be, for example, one which forms an image by an inkjet method.

[0083]

As described above, in the automatic document feeder of the present invention, the reversing means and the ejecting means are individually provided, and the horizontal distance from the document reading position to the reversing means is greater than the horizontal distance.
By arranging the reversing means and the discharging means such that the horizontal distance from the document reading position to the discharging means is longer, the reversing means can be arranged closer to the reading position, so that the document having a shorter length in the conveying direction is arranged. Can be handled and the transport path can be shortened, so that the reading time can be shortened. Further, in the automatic document feeder of the present invention, since the discharging unit can be arranged away from the reading position, the visibility of the document discharged to the discharging unit by the discharging unit can be improved.

Further, since the image forming apparatus of the present invention is equipped with the above-mentioned automatic document feeder, it is possible to form an image on the basis of a document whose conveyance direction is short, and the whole image including the image reading time. It is possible to shorten the image forming time. Further, the image forming apparatus of the present invention is capable of easily collating a document after image reading with an image-formed product (for example, a copy) based on this document because of high visibility of the document after image reading. it can.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an automatic document feeder according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing a flow of operations when reading one side of a document.

FIG. 3 is a flowchart showing a flow of operations when reading both sides of a document.

FIG. 4 is a flowchart showing a flow of operations when reading both sides of a document.

FIG. 5 is a vertical sectional view schematically showing an example of an image forming apparatus according to the present invention.

FIG. 6 is a diagram schematically showing a conventional automatic document feeder.

FIG. 7 is a diagram schematically showing another conventional automatic document feeder.

[Explanation of Codes] 1 ... Automatic document feeder, 2 ... Stacking section, 3 ... Supplying means, 4 ... Discharging means, 5 ... Discharging tray (discharging section), 6
...... Reversing means, 24 ...... Switching member, 26 ...... Reversing upper roller, 27 …… Reversing lower roller, 30 …… Discharging upper roller, 3
1 ... discharging lower roller, 32 ... intermediate tray (intermediate supporting member), 50 ... image forming apparatus, 51 ... original reading means, 52 ... image forming section, 53 ... recording material feeding / conveying means,
54: recording material reversing means, D: document, N3: reversing nip, N4: discharging nip, R: document reading position

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H04N 1/00 108 H04N 1/00 108Q 5C072 1/04 1/12 Z (72) Inventor Takuya Eto Osaka Prefecture 1-22 Tamatsukuri, Chuo-ku, Osaka City F-term in Kyocera Mita Co., Ltd. (reference) 2H076 AA04 BA24 BA31 BA35 BA36 BA47 BA58 BA63 BA64 BA65 BB05 3F049 DA12 LA03 LA05 LA07 LB02 3F053 BA03 BA14 BA19 LA02 LA05 LA07 LB02 3F100 AA03 CA12 CA15 5C062 AB02 AB31 AB32 AD06 5C072 AA01 NA01 XA01

Claims (7)

[Claims] 1. A supply unit for supplying a document on a stacking unit to a document reading position, a discharging unit for discharging a document after reading to a discharge unit, and a document after being read upside down and re-supplied to the document reading position. An automatic document feeder including the reversing unit, the reversing unit being disposed below the stacking unit, and the discharging unit being disposed below the reversing unit. The automatic document feeder, wherein the inverting means and the discharging means are arranged such that the horizontal distance from the document reading position to the discharging means is longer than the horizontal distance to. 2. The reversing means includes a reversing upper roller and a reversing lower roller which are in contact with each other from a substantially vertical direction to form a reversing nip for nipping and conveying a document. Automatic document feeder. 3. The ejecting means includes an ejecting upper roller and an ejecting lower roller which are in contact with each other in a substantially vertical direction to form an ejecting nip for nipping and conveying a document. The automatic document feeder described in. 4. The automatic document feeder according to claim 3, wherein the reversal nip is located above the discharge nip. 5. The automatic document feeder according to claim 4, further comprising a switching member that takes a reversal position that guides the read document to the reversal nip portion and a discharge position that guides it to the discharge nip. . 6. The automatic apparatus according to claim 5, further comprising an intermediate support member for supporting, from below, an end portion side of the document which is held in the reversing nip and which is far from the document reading position. Document feeder. 7. An original reading means for reading an original at an original reading position, and an automatic original feeding means for supplying the original to the original reading position and unloading the read original.
An image forming unit that forms an image on a recording material based on the image information read by the document reading unit, and a recording material feeding / conveying unit that supplies the recording material to the image forming unit and carries out the recording material after the image formation. An image forming apparatus comprising: an automatic document feeder, wherein the automatic document feeder is the automatic document feeder according to any one of claims 1 to 6.