JP3801768B2 - Automatic document feeder - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an automatic document feeder mounted on PPC, FAX, and other peripheral devices.
[0002]
[Prior art]
Conventionally, as shown in FIG. 2, the automatic document feeder 102 is, for example, a single-side mode in which only the first image surface (front surface) of the document 1 is read, and the reading of the first and second image surfaces (front and back surfaces). It is mounted on a main body 100 of a copying machine or the like having a duplex mode for performing. Then, a first transport path R1 having a pull-out roller 8 and a pull-out driven roller 9 on the transport path, and a second transport path having an auxiliary roller 14, an auxiliary driven roller 15, a paper discharge roller 16, and a paper discharge lower driven roller 17 on the transport path. A third transport path R3 which is a switchback path having a transport path R2, a reverse roller 21 and a reverse driven roller 22 on the transport path, and a fourth transport path having a paper discharge roller 16 and a paper discharge driven roller 18 on the transport path. R4, and the switching claw 19 is moved up and down by a solenoid (not shown) to switch the transport path on which the document 1 is transported according to the reading mode.
[0003]
In the duplex mode, the document 1 set on the document table 2 so that the first image surface (front surface) faces upward is fed from the top document to the separation belt 6 by a signal from the main body 100. The sheets are separated one by one in order and conveyed by the procedures (a) to (c) shown in FIG. First, as shown in FIG. 3A, the document 1 passes through the first transport path R <b> 1 and is transported to the document reading position on the contact glass 101 by the transport belt 13, and the reading unit 10 moves over the surface of the document 1. read. Further, the document 1 after the front side reading is conveyed to the intermediate tray 23 through the second conveyance path R2 and the third conveyance path R3. At this time, the switching claw 19 is at the B ′ position, and the document 1 is guided to the third transport path R3 by the upper guide surface 19e. Next, as shown in FIG. 3B, the document 1 after reading the surface returns to the third transport path from the intermediate tray 23 by the reverse roller 21 and the reverse driven roller 22 being switched back. Through the four transport paths R4 and the first transport path R1, the transport belt 13 transports again to the document reading position on the contact glass 101, and the back surface of the document 1 is read. At this time, the switching claw 19 moves upward from the second transport path R2 side and is at the B position so that the document 1 returning from the intermediate tray 23 is transported from the third transport path R3 to the fourth transport path R4. Then, the document 1 is guided to the reading unit 10 by the upper guide surface 19e. Further, the document 1 after the back side reading is conveyed to the intermediate tray 23 through the second conveyance path R2 and again through the third conveyance path R3. At this time, the switching claw 19 switches from the B position to the B ′ position, and guides the document 1 to the third transport path R3 by the upper guide surface 19e. Next, as shown in FIG. 3C, the switching claw 19 is switched from the B ′ position to the B position, and the reverse roller 21 and the reverse driven roller 22 are switched back. In order to arrange the discharge order of the originals 1, the intermediate tray 23 returns to the third conveyance path R 3, and further passes through the fourth conveyance path R 4 and the first conveyance path R 1 and is again conveyed on the contact glass 101 by the conveyance belt 13. Then, it passes through the second transport path R2 and is guided to the paper discharge stack unit 20. At this time, the document 1 is guided to the paper discharge stack unit 20 by the lower guide surface 19 f of the switching claw 19.
[0004]
[Problems to be solved by the invention]
In the prior art, the document after duplex scanning in duplex mode is reversed by passing again through the scanning path (including the first transport path and the second transport path) from the intermediate tray, and then the paper discharge stack unit (discharge). Since the paper is discharged to the paper holding means), there is a problem that it takes extra time for conveyance and a long document processing time.
[0005]
The object of the present invention is to improve such a problem and greatly reduce the document processing time by shortening the transport distance when transporting the document after duplex scanning in the duplex mode to the discharge stack unit. It is an object of the present invention to provide an automatic document feeder capable of performing the above.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, an automatic document feeder according to the present invention includes a conveying unit that conveys a document to a document reading position and a duplex mode that reads the first and second image surfaces of the document, after reading the first image surface. Intermediate holding means for temporarily holding the original or the first and second image planes after reading, and a lower side of the intermediate holding means, and a single-side mode for reading only the first image plane after reading the first image plane with document, and a paper discharge holding means for temporarily holding the first and the document of the second image plane after reading in duplex mode, a switching claw for switching the document conveying path upstream near the conveying path of the intermediate holding means, The switching claw includes a first guide surface that guides the original after reading the first image plane in the duplex mode or the original after reading the first and second image planes to the intermediate holding means, and the intermediate hold in the duplex mode. A second guide surface for reversing the original document after reading the first and second image planes temporarily held by the means and guiding it to the paper discharge holding means, and the original document after reading the first image surface in the single-side mode. It has a third guide surface for guiding the sheet discharge holding means, guide surface formed between the downstream end of the guide surface of the upper and lower surfaces, the first and has been held temporarily in the intermediate holding means When the original after reading the second image surface is reversed and guided to the discharge holding means, the leading edge of the original is formed in a concave shape so as to be directed toward the discharge holding means with respect to the original reading position. It is characterized by that.
[0007]
In order to achieve the above object, an automatic document feeder according to the present invention includes a first image plane in a duplex mode for feeding a document to a document reading position and a first and second image plane of the document. An intermediate holding means for temporarily holding the original after reading or the original after reading the first and second image surfaces, and the first image surface reading in a single-side mode which is arranged below the intermediate holding means and reads only the first image surface. A paper discharge holding means for temporarily holding the subsequent original and the original after reading the first and second image surfaces in the duplex mode; and a switching claw for switching the original conveyance path on the conveyance path near the upstream of the intermediate holding means. provided, wherein the switching claw, a first guide surface for guiding the document after the document or the first and second image plane reading after the first image plane reading in duplex mode to said intermediate holding means, the double-sided mode A second guide surface that reverses the original after reading the first and second image planes temporarily held in the intermediate holding means and guides it to the paper discharge holding means, and the original after reading the first image plane in the single-sided mode the have a third guide surface for guiding to the sheet discharging holding means, said second guide surface, the first and second image plane after reading that has been temporarily held in the intermediate holding means in duplex mode When the document is reversed and guided to the discharge holding unit, the leading end of the document is formed in a concave shape so as to be directed toward the discharge holding unit with respect to the document reading position .
[0008]
Further, in the automatic document feeder of the present invention, when the third guide surface guides the document after reading the first image surface in the single-sided mode to the discharge holding unit, the leading end of the document is held by the discharge holding. It is formed in a concave shape so as to go to the means .
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a configuration diagram of an automatic document feeder according to an embodiment of the present invention, FIG. 4 is a diagram showing a conveyance path in the duplex mode of the automatic document feeder of FIG. 1, and FIG. 5 is an automatic diagram of FIG. It is a figure which shows operation | movement of the switching nail | claw in the single side / double side mode of a conveying apparatus. The automatic document feeder 102 according to this embodiment includes a transport unit (= pull-out roller 8, pull-out driven roller 9, transport belt 13 and the like) that transports the document 1 to the document reading position, and a first image surface (front surface) of the document 1. ) And the second image surface (rear surface) in the duplex mode for reading a single-sided original or an original after double-sided reading (= intermediate tray 23) and an intermediate tray 23 disposed below the intermediate tray 23. A paper discharge holding means (= discharge stacking portion 20) for temporarily holding the original after the single-sided reading in the single-sided mode for reading the first image surface and the double-sided reading in the double-sided mode; And a switching claw 19 for switching the conveyance path. In the present embodiment, the image information is read by the reading unit 10 on the main body 100 side while conveying the document to the document reading position. For example, an exposure unit such as a light source and a mirror (not shown) is provided, and the image information of the document 1 is read by the CCD 4 or the like.
[0010]
The switching claw 19 reverses the first guide surface 19a that conveys a document after single-sided and double-sided reading in the duplex mode to the intermediate tray 23, and the document after duplex scanning called from the intermediate tray 23 in the duplex mode. A second guide surface 19b (= reversing means) that is held in the paper discharge stack unit 20 and a third guide surface 19c that holds a document after single-sided reading in the single-sided mode in the paper discharge stack unit 20, The second guide surface 19b is formed between the downstream ends of the upper and lower guide surfaces 19a and 19c. The switching claw 19 has a substantially triangular cross section, and the second guide surface 19b and the third guide surface 19c are formed in a concave shape. Further, the switching claw 19 rotates around the rotation shaft 25 by suction of a solenoid (not shown). At this time, the upstream ends of the first and third guide surfaces 19a and 19c move up and down more greatly, and are switched to the C position or the C ′ position. With such a configuration, only the vertical movement of the switching claw 19 guides the document from the third transport path R3 to the fourth transport path R4, or from the second transport path R2 to the third transport path R3, and the intermediate tray. The document after double-sided reading from 23 can be immediately reversed.
[0011]
In the present embodiment, as in the prior art, the first conveying path R1 having the pull-out roller 8 and the pull-out driven roller 9 on the conveying path, and the auxiliary roller 14, the auxiliary driven roller 15, and the paper discharge roller on the conveying path. 16, a second transport path R2 having a driven roller 17 under discharge, a third transport path R3 that is a switchback path having a reverse roller 21 and a reverse driven roller 22 on the transport path, and a discharge roller on the transport path. 16 and a fourth transport path R4 having a driven roller 18 on the paper discharge.
[0012]
Next, the document conveying operation in this embodiment will be described. The document 1 set on the document table 2 so that the first image surface (front surface) faces upward is positioned by the front end of the document 1 abutting against the paper feed guide plate 3. Then, a signal from the main body 100, for example, a start signal generated by pressing a start button (not shown) on the operation unit on the main body 100 side, is fed one by one from the top document. At this time, the bottom plate 4 lifts the paper feed side end of the document 1 from below, rotates around a fulcrum 4a by a solenoid (not shown), moves upward in the direction of arrow A, and the document 1 contacts the calling roller 5 and pressurizes. To behave. The pressed originals 1 are fed by a calling roller 5 in order from the top to a separation unit including a separation belt 6, a separation roller 7, and a guide member 50 that also serves as an exterior, and is separated one by one. At this time, the separation belt 6 is rotated forward in the sheet feeding direction by driving a sheet feeding motor (not shown), and the separation roller 7 is rotated in the reverse direction to prevent the next original from entering the separation section. A pull-out roller 8 and a pull-out driven roller 9 convey the toner toward the conveying belt 13. The document thus separated is transported to the document reading position on the contact glass 101 through the first transport path R1 having the pull-out roller 8 and the pull-out driven roller 9 on the transport path. The original reading position is conveyed by a conveying belt driving roller 11, a conveying belt driven roller 12, and a conveying belt 13 stretched over them by driving of a driving motor (not shown). At this time, the document enters between the conveyance belt 13 and the contact glass 101, and the conveyance force of the document is obtained by the difference in the friction coefficient between the conveyance belt 13 and the document and between the contact glass 101 and the document. Note that the single-sided / double-sided mode selection setting is made in advance by an operator at an operation unit (not shown) on the main body 100 side.
[0013]
In the present embodiment, when the duplex mode is set, as shown in FIG. 4A, the sheet is separated by the separation unit and conveyed to the document reading position through the first conveyance path R1 as described above. After the image information on the surface of the original 1 is read by the reading unit 10, the second conveyance path R <b> 2 includes an auxiliary roller 14, an auxiliary driven roller 15, a paper discharge roller 16, and a paper discharge lower driven roller 17. And the leading edge of the document is detected by the paper discharge sensor 24. The rollers 14 and 16 are driven by a paper discharge motor (not shown). At this time, as shown in FIG. 5A, the switching claw 19 is lowered to the C ′ position by the suction of the solenoid. As a result, the document passes along the first conveying surface R3 that is a switchback path having the reversing roller 21 and the reversing driven roller 22 along the first guide surface 19a, and the rear end of the document is the guide end 19d (first first). Until the first guide surface 19a and the second guide surface 19b cross), the reversing roller 21 and the reversing driven roller 22 convey it onto the intermediate tray 23. Stop. In this way, the document is temporarily held on the intermediate tray 23.
[0014]
Next, as shown in FIG. 4B, the original after one-side reading once held on the intermediate tray 23 passes through the third conveyance path R3 by the reverse rotation of the reverse roller 21 and the reverse driven roller 22. It is conveyed again to the reading position. At this time, the switching claw 19 returns from the C ′ position shown in FIG. 5A to the C position shown in FIG. 5B by releasing the solenoid. That is, after one-side reading in FIG. 4A, the trailing edge of the document passes through the paper discharge sensor 24, and a certain time (the time until the trailing edge of the document passes through the paper discharge roller 16 and reaches the switching claw 19) has elapsed. Thereafter, the solenoid is released to return to the C position. Thus, the switching claw 19 returns to the C position, and the reversing roller 21 and the reversing driven roller 22 rotate reversely, and the original after reading the surface once held on the intermediate tray 23 follows the first guide surface 19a. Then, the sheet enters a fourth transport path R4 having a paper discharge roller 16 and a paper discharge follower roller 18 on the transport path. At this time, since the discharge roller 16 is stopped, when the leading edge of the document enters the nip portion between the discharge roller 16 and the discharge upper driven roller 18, the correction of the document conveyance posture (skew abutting correction) is performed. . After completion of the abutting correction, the document 1 is transported from the fourth transport path R4 to the document reading position through the first transport path R1, and the image information on the second image surface (back surface) is read by the reading unit 10. . When the original after reading the back side of the original is discharged as it is to the paper discharge stack section 20, the back side of the original is stacked downward and the page order of the original is incorrect. Therefore, the original 1 is inverted so that the front side of the original is stacked downward It is necessary to let Therefore, the document after double-sided reading held between the document reading position by the auxiliary roller 14 and the auxiliary driven roller 15 and transported through the second transport path R2 is once held on the intermediate tray 23 again. At this time, as shown in FIG. 5B, the switching claw 19 is lowered from the C position to the C ′ position by the solenoid. As a result, the original passes along the first guide surface 19a along the second transport path R2, and further passes through the third transport path R3 onto the intermediate tray 23, and the rear end of the original passes through the guide end 19d. It is once held as described above.
[0015]
Next, as shown in FIG. 4C, the document after double-sided reading once held on the intermediate tray 23 returns to the third transport path R3 by the reverse rotation of the reverse roller 21 and the reverse driven roller 22. It strikes against the switching claw 19 and reverses and is guided downward to be discharged to the paper discharge stack unit 20. At this time, as shown in FIG. 5C, the switching claw 19 is held at the C ′ position by the solenoid, and the document is reversed by the concave second guide surface 19b.
[0016]
In the present embodiment, when the single-sided mode is set, the document 1 conveyed to the document reading position through the first conveyance path R1 as described above reads image information by the reading unit 10. After that, the sheet passes through the second transport path R2 having the auxiliary roller 14, the auxiliary driven roller 15, the paper discharge roller 16, and the paper discharge driven roller 17 and is discharged to the paper discharge stack unit 20. At this time, the switching claw 19 is set at the C position as shown in FIG. 5D, and the document nipped and conveyed by the paper discharge roller 16 and the paper discharge driven roller 17 is transferred to the third guide surface. It hits 19c, is guided downward, and is discharged as it is to the discharge stack unit 20 without being reversed.
[0017]
According to the present embodiment, the switching claw 19 is arranged in the vicinity of the upstream side of the intermediate tray 23, and after double-sided reading once held on the intermediate tray 23 by the second guide surface 19b (= reversing means) of the switching claw 19 Since the original is reversed and discharged to the paper discharge stack unit 20, the original after double-sided reading does not go through the original reading position again. That is, in the prior art, the original after double-sided reading passes from the intermediate tray 23 through the third conveyance path to the fourth conveyance path R4 to the first conveyance path R1 to the second conveyance path R2. In the embodiment, since the guide tray 19b is reversed from the intermediate tray 23 and is immediately guided to the paper discharge stack unit 20, the conveyance distance of the document after the double-sided reading is shortened, and the document processing time is greatly shortened. Can do.
[0018]
Further, according to the present embodiment, the cross-section of the switching claw 19 has a substantially triangular shape, the first guide surface 19a that conveys the document conveyed via the reading position to the intermediate tray 23, and single-sided reading in the single-sided mode. Since the document is reversed by using the second guide surface 19b other than the third guide surface 19c for discharging the subsequent document to the paper discharge stack unit 20, after the double-sided reading is performed only by the vertical movement of the switching claw 19 by the solenoid. The original transport distance can be shortened, and the original after one-sided reading can be quickly discharged even in the single-sided mode. Therefore, the document processing time in the duplex mode can be made closer to that in the simplex mode. Since a concave surface is formed at the position where the second guide surface 19b comes into contact with the original, the original after double-sided reading is easily reversed, which is suitable for aligning the stack direction and the stack surface. In addition, since the third guide surface 19c is also formed with a concave surface, when the original after one-sided reading is discharged as it is without being reversed, the front end of the original is directed toward the stack surface, thereby improving the discharge stacking property. It is suitable for improvement.
[0019]
【The invention's effect】
As described above, according to the present invention, the document conveyance path is switched over the conveyance path in the vicinity of the upstream of the intermediate holding means for temporarily holding the document after reading one side (front side) or both sides (front and back) in the duplex mode. A switching claw is arranged, and the switching claw has a reversing means for reversing the document temporarily held by the intermediate holding means, so that the document after double-sided scanning can be reversed by the switching claw, and the document is read again. Never go through the position. More specifically, the switching claw includes a first guide surface that guides a document after single-sided or double-sided reading in the double-sided mode to the intermediate holding unit, and after double-sided reading temporarily held in the intermediate holding unit in the double-sided mode. A second guide surface (= reversing means) for reversing and guiding the document to the discharge holding means, and a third guide surface for guiding the document after one-sided reading in the single-side mode to the discharge holding means, The first and third guide surfaces provide guidance when the document is conveyed between the document reading position and the intermediate holding unit, and are formed between the downstream ends of the first and third guide surfaces. On the second guide surface, the original after double-sided reading temporarily held by the intermediate holding unit is reversed and guided to the discharge holding unit, so that the original after double-sided reading is conveyed to the discharge holding unit in the double-side mode. The transport distance can be greatly reduced. Therefore, the document processing time in the duplex mode can be made closer to that in the single-sided mode, and the document processing time can be greatly shortened.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of an automatic document feeder according to an embodiment of the present invention.
FIG. 2 is a configuration diagram of a conventional automatic document feeder.
FIG. 3 is a diagram illustrating a conveyance path in the duplex mode of the automatic document conveyance device of FIG. 2;
4 is a diagram illustrating a conveyance path in a duplex mode of the automatic document conveyance device of FIG. 1. FIG.
5 is a diagram illustrating an operation of a switching claw when the automatic document feeder of FIG. 1 is in a single-sided / double-sided mode.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Document 8 Pull-out roller 9 Pull-out driven roller 13 Conveyor belt 14 Auxiliary roller 15 Auxiliary driven roller 16 Paper discharge roller 17 Paper discharge lower driven roller 18 Paper discharge upper driven roller 19 Switching claw 19a-19c 1st-3rd guide surface 19d Guide End 21 Reverse roller 22 Reverse driven rollers R1 to R4 First to fourth transport paths

Claims (3)

In the duplex mode in which the document is transported to the document reading position and the first and second image surfaces of the document, the document after reading the first image surface or the document after reading the first and second image surfaces is temporarily stored. An intermediate holding means for holding, a paper discharge holding means for temporarily holding the original after reading the first and second image surfaces in the duplex mode, and a switching claw for switching the original conveying path on the conveying path near the upstream of the intermediate holding means equipped with a door,
The switching claw guides the original when the original after reading the first image plane or the original after reading the first and second image planes is transported between the original reading position and the intermediate holding means. The original after reading the first and second image planes formed between the upper and lower guide surfaces and the downstream end of the upper and lower guide surfaces and temporarily held by the intermediate holding means is reversed to have a guide surface for guiding the sheet discharging the holding means,
A guide surface formed between the downstream ends of the two upper and lower guide surfaces reverses the original after reading the first and second image surfaces temporarily held by the intermediate holding unit, and the discharge holding unit. An automatic document feeder, wherein the leading edge of the document is formed in a concave shape so that the leading edge of the document is directed toward the discharge holding means with respect to the document reading position . In the duplex mode in which the document is transported to the document reading position and the first and second image surfaces of the document, the document after reading the first image surface or the document after reading the first and second image surfaces is temporarily stored. An intermediate holding means for holding, an original document after reading the first image surface in the single-sided mode for reading only the first image surface, and after reading the first and second image surfaces in the double-sided mode. comprising a sheet discharge holding means for temporarily holding the original, and a switching claw for switching the document conveying path upstream near the conveying path of the intermediate holding means,
The switching claw includes a first guide surface that guides the original after reading the first image surface in the duplex mode or the original after reading the first and second image surfaces to the intermediate holding means, and the intermediate holding in the duplex mode. A second guide surface for reversing the original document after reading the first and second image planes temporarily held by the means and guiding it to the paper discharge holding means, and the original document after reading the first image surface in the single-side mode. have a third guide surface for guiding the sheet discharging the holding means,
The second guide surface is used when the original after reading the first and second image surfaces temporarily held by the intermediate holding unit in the duplex mode is reversed and guided to the discharge holding unit. An automatic document feeder, wherein a leading end is formed in a concave shape so as to be directed toward the discharge holding unit with respect to the document reading position . The third guide surface is formed in a concave shape so that the leading edge of the document is directed to the discharge holding means when the original after reading the first image surface is guided to the discharge holding means in the single-sided mode. The automatic document feeder according to claim 2.

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