JPH0543090A - Sheet feeding device - Google Patents

Abstract

PURPOSE:To ease removing jammed sheets or resetting and restarting sheets by driving a drive means during the return of a feeding means to an initial condition when a feeding stop for the sheets with the feeding means is detected. CONSTITUTION:When a pickup roller 42 is descended with rotating to contact a document on a document tray 31, the document is sent forward to be led to a reading part via register roller 451, etc. When a time, longer than the expected passing time for a L-size document, is passed after the document is feeding-started from the register roller 451, feeding abnormality due to jamming, etc., is judged to immediately stop a second drive motor M2. On the other hand, a first drive motor M1 is reversed on jamming occurrence, and an oscillation arm member 821 is oscillated due to the reversal to ascend the pickup roller 42 to be separated from the document. Concurrently, a timer is set and the motor M1 is stopped by time-up, thus easing jam-treating or sheet-setting.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device such as an automatic document feeding device for feeding a document to a platen such as a copying machine or an image reader.

[0002]

2. Description of the Related Art Conventionally, an automatic document feeder for feeding a document to a platen of a copying machine and discharging the document after completion of copying is provided with a feeding means for feeding a document stacked on a document tray and a feeding means for feeding the document. Whenever the means feeds the original, the feeding means drives the feeding means to an initial position separated from the original and a feeding position for coming in contact with the original and feeding the original, and one original fed by the feeding means. A separating means for separating the sheets into a sheet, a conveying means for conveying the originals separated by the separating means on the platen, and a sheet discharging means for discharging the originals on the platen after the copying is completed. It is attached to the side via a hinge so that it can be opened and closed on the platen.

This automatic document feeder is constructed so that if a document being conveyed is jammed in the conveyance path or the platen is opened during conveyance, the drive motor and driving means are stopped and the document is not conveyed. There is.

[0004]

Therefore, if the document is jammed or the platen is opened while the feeding unit is in contact with the document, the operation of the driving unit is stopped and the feeding unit is fed. Remains in contact with the sheet.

Therefore, even if the original is set again,
There is a problem in that the feeding means becomes an obstacle and it takes time to reset the feeding means.

An object of the present invention is to allow the minimum feeding means to be separated from the sheet even if the feeding operation is suddenly interrupted, which makes it easy to remove the jammed sheet and reset the sheet.
The purpose of the present invention is to obtain a sheet feeding apparatus that does not need to perform the initial operation of the feeding unit again when restarting.

[0007]

In order to achieve the above-mentioned object, the present invention provides a sheet feeding means for feeding a stacked sheet and a sheet feeding means each time the sheet feeding means feeds a sheet. In a sheet feeding device having a driving means for driving an initial position separated from the sheet and a feeding position for contacting and feeding the sheet, detection means for detecting sheet feeding suspension by the feeding means, and this detection A control means for driving the drive means at least while the sheet feeding means returns to the initial state when the sheet feeding stop is detected by the sheet feeding means.

Further, a feeding means for feeding the stacked sheets, an initial position in which the feeding means is separated from the sheet every time the feeding means feeds the sheet, and a sheet which is in contact with the sheet and is fed. A sheet feeding device including a driving unit that drives to a feeding position and a separating unit that separates the sheets fed by the feeding unit into a sheet, and detects a sheet feeding stop by the feeding unit. And a drive means for driving the driving means in a state where the separating operation by the separating means is stopped while the feeding means returns to the initial position at least when the detecting means detects the sheet feeding stop. Control means may be provided.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A sheet feeding device of the present invention applied to an automatic document feeding device for feeding a document to an image forming apparatus such as a copying machine will be described below with reference to the drawings.

<Structure> As shown in FIG. 1, the automatic document feeder F is placed on the platen P of the copying machine M and has an outer shape of a substantially square shape so that it can be accommodated within the upper surface profile of the copying machine M. It is compactly configured.

As shown in FIGS. 1 and 2, an automatic document feeder F
Is a conveying means for covering a certain area corresponding to approximately half of the platen P of the copying machine M, for example, the conveying section 10, a platen cover section 20 for covering the remaining area of the platen P, and an upper portion of the platen cover section 20. Document tray unit 3 provided
0, a separation feeding unit 40 which is a portion to which the sheet feeding apparatus of the present invention is applied, which separates and feeds the document set on the document tray unit 30 toward the platen P, and the conveyance unit 1.
A paper ejection unit 50 that receives an exposed document conveyed by 0 and ejects it from the platen P, a paper ejection tray unit 60 that stores the document ejected by the paper ejection unit 50, and an automatic document feeder F to the platen P. A hinge 70 and a drive / control unit 80 that openably and closably support the above.

FIG. 18 is an automatic document feeder F in FIG.
Is shown above the platen P, and the effective reading range (reading section T: length X
(Between −Z) is defined, and one end of the reading unit is set as the reading reference point X. When copying, this reference point X
By arranging one end of the document D together with the document D, a copy corresponding to the document can be obtained.

The reading section T corresponds to the maximum size that can be copied, and is indicated by a chain line in the drawing. For example, A3
The size (297 mm x 420 mm) is the maximum size that can be copied,
Here, A3 size is a large size (large size or L size), and A4 size (210 mm × 297 mm) is a small size (S
Size). Therefore, the total length (X
-Z) is for a large size original (L size original), and half (between XY) is for a small size original (S size original). In FIG. 18, a small-sized document D is positioned in the reading section T in accordance with the reference point.

Further, as shown in FIG. 1, the automatic document feeder F is provided with two drive motors M1 and M2.

The drive motor M1 is drivingly connected to the separating / feeding section 40, and the driving motor M2 is drivingly connected to the conveying section 10. However, in the present embodiment, the registration roller 451 described later is connected to the drive motor M2, but it is assumed to belong to the category of the separation feeding unit 40.

The device F is provided with several sensors. Of these, as shown in FIG. 1, the sensor S1 is an empty sensor for detecting the presence or absence of a document set on the document tray section 30. Further, the sensor S2 is a registration sensor provided on the way of the conveyance path for conveying the original separated into one sheet by the separating / feeding unit 40 to the platen P and detecting the leading edge or the trailing edge of the original passing through the conveyance path. is there. Further, the sensor S3 is a switchback sensor that detects the leading edge or the trailing edge of the document conveyed in the paper discharge unit 50.

Further, as shown in FIG. 5, the sensor S4 is a photo sensor for detecting the rotation amount of the interrupter 871 provided on the output shaft 86 of the drive motor M2. The sensor S5 is provided on the hinge portion 70 as shown in FIG.
The automatic document feeder F detects with respect to the copying machine M whether the platen P is in the open state with the platen P open, or as shown in FIG.

After the document is fed from the registration roller 451, if the trailing edge is not detected by the registration sensor S2 by the expected required time for passing the L size document, it is determined that a feeding trouble has occurred, and the power source is turned on. When cut off, the drive motor M2 is immediately stopped. That is, the registration sensor S2 and the photo sensor S4 of the interrupter 871 serve as a detection unit for detecting the stop of the document feeding in this case.

The interruption of the feeding of the original document is caused by the sensor S caused by the opening of the original document feeding device F at the time other than the above-mentioned jam.
Detection by 5 is also included.

On the other hand, the drive motor M1 does not immediately stop even when the power is cut off, but stops after performing the reverse rotation operation for a predetermined minute time. The operation at this time will be described in detail in the operation description with reference to FIGS.

Next, the details of the configuration of each part will be described.

The document tray section 30 is shown in FIGS. 9 to 11, and a document tray 31 on which a document is placed, a pair of side end guides 32L and 32R for regulating the side ends of the document set on the document tray 31. It is composed of various types of sub-tray.

FIG. 9 shows the original sub-tray 34a.
And the discharge sub-tray 34b are integrated with a sub-tray body 34 formed by bending a thin rod member.

With such a structure, the original sub-tray 3
By pulling out 4a, at the same time, the paper discharge sub-tray 34
b is also pulled out at the same time, and when processing the L-size document, forgetting to pull out the paper discharge sub-tray 34b, and as shown in FIG. 12, the leading edge of the document comes from the paper discharge tray 61 side to the document tray 31.
It is possible to prevent an accident that the paper drips to the side and falls on the document tray 31 in some cases.

In the structure shown in FIG. 10, the original sub-tray 35, one end of which is connected to the shaft 351, and the paper discharge sub-tray 36, which is connected to the shaft 361, can be integrally projected and retracted through the connecting member 37. It was made like this. That is, the pinion 352 fixed to the shaft 351 is meshed with one rack portion 371 of the coupling member 37,
The pinion 362 fixed to the shaft 361 meshes with another rack portion 372. Then, for example, when the original sub-tray 35 is rotated clockwise to project as shown in the figure,
The coupling member 37 is moved leftward in the drawing by the clockwise rotation of the pinion, and the rack portion 372 rotates the pinion 362 clockwise. Then, the paper discharge sub-tray 36 is set in the same manner as the document sub-tray 35, and the paper discharge tray 61 is
Can be projected outward from.

Further, in FIG. 11, the document sub-tray 38 and the paper discharge sub-tray 39 are connected by a connecting wire 384 so that they can integrally project and retract.

On the original sub-tray 38 side, a locking projection 38a is provided so as to hold the projected position when pulled out, and a locking member 381 that engages with the locking projection 38a is a non-moving body part of the apparatus F. It is fixed to. Further, a retracting spring 391 for constantly urging the member 39 toward the retracted side is disposed on the side of the paper discharge sub-tray 39.

Both sub trays 38 and 39 are connected at their rear ends by a connecting wire 384,
The connecting wire 384 bypasses the wire guides 382 and 383 formed of an even number of rod members or roller members. It is important that the number of such wire guides is always an even number, and four or more wire guides can be formed depending on the arrangement positions of both sub-trays 38 and 39. However, in the case of an odd number, the moving directions of both sub trays are opposite to each other.

The separating / feeding section 40 is provided with an original feeding path R1 for guiding the separated original from the predetermined position of the platen P (point Y at the center of the reading section T) to the platen P. The feeding path R1 is partitioned by the guide plates 410 and 411.

A feed means, for example, a pickup roller 42, is provided at the entrance side of the feed path R1 so as to be able to move forward and backward in the document tray 31, and the guide rollers 410 and 411 form a feed roller 43 and a separation belt. 44 is the feeding path R
1 are in contact with each other and are arranged so as to overlap each other. Also, the feeding path R
Registration roller 451 and pinch roller 45 on the exit side of 1.
2 are provided facing each other.

A document stopper 46 provided at the entrance of the feeding path R1 so as to be movable back and forth with respect to the guide plate 411, and a document tray 3 in cooperation with the empty sensor S1.
A sensor lever 47 for detecting the presence / absence of a document on the sheet 1 is provided, and a registration sensor S2 is provided between the feeding roller 43 and the registration roller 451 of the feeding path R1.

A document stopper 46, a pickup roller 42, a feeding roller 43, which are provided along the feeding path R1,
As shown in FIG. 4, the separation belt 44 is configured to rotate / rotate the power from the drive motor M1 in a predetermined direction via belt drive transmission means 810, 811, a plurality of gears G, and the like.

Assuming that one original is pulled out from the original tray 31 and sent to the feeding path R1, the rotation (normal rotation) of the drive motor M1 is transmitted to the shaft 831 via the gears G2, G3, and G4. The rotation of the shaft 831 causes the drive transmission member 8 to rotate.
32 is driven to rotate the shaft 833 in a predetermined direction. Then, since the document stopper 46 moves to the position shown by the chain line in FIG. 2, the document on the document tray 31 can be separated and fed.

Further, the pick-up roller 42 has a shaft 82 for holding the feeding roller 43 by means of a swing arm member 821.
Since it is pivotally supported by the lever 836, the lever 836 is fixed to the shaft 831 and comes into contact with the swing arm member 821.
Rotation causes the swing arm member 821 to rotate downward toward the document and contact the surface of the document.

Further, the normal rotation of the drive motor M1 is determined by the gear G.
It is transmitted to the shafts 82 and 84 via 1, G5, G6, and G7 to rotate the feeding roller 43 and the separation belt 44 in different directions. A one-way clutch 822 is incorporated in the gear G7, and even if the rotation of the gear G7 is stopped, when the document is forcibly conveyed forward, the feeding roller 4
3 is adapted to rotate following the forward movement of the document.

Further, the one-way clutch 823 is also attached to the gear G6.
Even if the rotation of the gear G5 is stopped, when the document is forcibly conveyed to the front, the separation belt 44 rotates following the advance of the document.

Further, the gear G1 also has a one-way clutch 824.
When the drive motor M1 rotates in the reverse direction, the gear G1 idles, and the drive force is not transmitted to the rollers 42 and 43 and the separation belt 44, but the drive force is applied to the document stopper 46 and the lever 836. This is transmitted, and the drive motor M1 is rotationally driven in the direction opposite to that in the normal rotation.

By the structure of the separating and feeding section 40 described above,
When the drive motor M1 rotates normally, the pickup roller 42
Only the feeding roller 43 rotates in the forward direction (original conveying direction), and the separation belt 44 rotates in the reverse feeding direction. As a result, the documents placed on the document tray 31 are fed one by one to the feeding path R1.
Transport from the entrance to the exit.

When the drive motor M1 rotates in the reverse direction, the lever 836 rotates to separate the pickup roller 42 from the surface of the original.

When the drive motor M1 is rotated in the reverse direction by the one-way clutch 822, the separating means including the separating belt 44 and the feeding roller 43 does not rotate.

The state in which the pickup roller 42, which is the feeding unit, is separated from the original surface as described above is referred to as the initial state of the feeding unit.

The document conveying section 10 as a conveying means is an endless belt-shaped conveying belt 13, a pair of pulleys 11 and 12 for driving the conveying belt 13 so as to be able to rotate forward and backward, and the conveying belt 1.
3 and a plurality of press rollers 14 for pressing the platen P against the platen P. Further, the document transporting section 10 has a size sufficient to cover approximately half (between X and Y) of the L size document from the reading reference point X side on the upper surface of the platen P. That is, the conveyor belt 13 is provided at the exit of the feeding path R1, and forms a conveying path R2 between the conveyor belt 13 and the platen P. The entrance of the conveyance path R2 (the exit of the feeding path R1) is located at substantially the center (point Y) of the reading section T, and the exit is at the reading reference point X defined at the downstream end of the reading section T in the document feeding direction. It is almost located.

Here, the pulley 11 will be described with reference to FIGS.
The detailed configuration will be described.

In FIG. 21, the pulley 11 is an arm shaft 16
It is pivotally supported at the tip of a pulley shift arm 15 which is pivotally supported by the. And the pulley shift arm 1
5 is vertically tensioned by an upper spring 18 and a lower spring 19, and is normally in a lower normal position by the lower spring 19 as shown in FIG. On the other hand, the upper spring 18 is coupled to the shaft end of the shift solenoid 17 and moves upward as shown in FIG. 19 when the shift solenoid 17 is excited.

As shown in FIG. 19, even when the pulley 11 is lifted up by the excitation of the solenoid 17, the position of the press roller 14 is not changed and the conveyor belt 13 is moved to the platen P.
Hold it on top.

However, when the document is fed, the process shown in FIG.
As described above, the belt pulley 11 is lifted as indicated by the upward arrow A1, and when the L size original is inserted under the platen cover 21, the belt pulley 11 moves upward as shown in the figure. Then, the gap g is made sufficiently large.

When the original is set on the platen P, the belt pulley 11 descends in the direction of arrow A2 as shown in FIG. 20, and the gap g becomes substantially zero.

The end 21a of the platen cover 21 is shown in FIG.
It is sharply cut like the above and is suitable for removing gaps.

If the end 21a of the platen cover 21 is sharply cut as shown in FIG. 8, there is also an effect that the shadow of the platen cover 21 due to the illumination lamp of the copying machine M is less likely to be formed. In order to prevent the shadow of the end portion of the platen cover 21 in the irradiation direction of the illumination lamp, it is preferable to illuminate the end portion 21a side from, for example, the lower left portion of FIG. 19 (arrow L in FIG. 8). ..

The original feeding section 10 allows the feeding path R1
The document discharged from the exit of the document can be conveyed to the reference point X of the reading section T, or can be conveyed in front of the reference point X and ejected, or can be conveyed in the opposite direction.

As shown in FIGS. 2 and 6, the document feeder 1
Behind the exit of 0 (reference point X), the document transport unit 10
A paper discharge section 50 is provided in series.

The paper discharge section 50 has a pair of side plates 58, and a pair of pulleys 52 and 53, and a rolling roller 54 that rolls on the conveyor belt 13 and transmits a driving force.

A paper discharge belt 5 is provided between the pulleys 52 and 53.
1 is stretched, and the driving force of the rolling contact roller 54 is transmitted to the pulley 53 via a gear mechanism. Further, guide members 55 and 56 for guiding the document discharged from the exit of the conveyance path R2 to the discharge tray unit 60 are provided.
A paper discharge path R3 for guiding the document sent from the document transporting section 10 is formed between 5 and 56.

However, the rolling contact roller 54 is the conveyor belt 13
The driving force in the sheet discharging direction from the sheet is transmitted, but the driving force at the time of reverse feeding is not transmitted by the one-way clutch provided inside.

A leaf spring member 57, one end of which is fixed to the guide member 55 and the other end of which presses the document against the paper discharge belt 51, is provided at a position away from the facing portion of the paper discharge belt 51. The pulleys 52 and 53 are entirely made of a low-friction material, and a high-friction ring member 59a (59b) is fitted in the central portion as shown in FIG. The part that slides is formed on the ribs 52a (53a), which has a large pressing force against the document, and at the time of paper ejection which is often seen when sticking to the cylindrical surface of the pulley as in the past. I was able to eliminate the phenomenon of the rear end remaining.

The contact roller 54 is biased directly by a spring member (not shown) against the surface of the conveyor belt 13 at a position facing the driven pulley 12.

The paper output tray 61 of the paper output tray section 60 is shown in FIG.
As described above, it extends from above the conveying unit 10 to above the separating and feeding unit 40, and the leading end portion thereof is the document tray unit 30.
It is supposed to overlap on top of. Therefore, in this state, the L-size original or the like having a particularly large size which is ejected vigorously from the paper ejecting section 50 may have its leading end hanging on the original tray section 30 as shown in FIG. 12 or dropping in some cases. Therefore, as described above, the discharge sub-tray 65b which can be projected and retracted in association with the document sub-tray 65a and the like is attached so that it can be pulled out when processing an L-size document.

Next, as shown in FIGS. 2 and 8, the platen cover portion 20 is provided below the separating / feeding portion 40 on the platen P side, and the platen cover 21 is installed in parallel with the platen P.
And supporting members 22 and 23 for supporting the platen cover 21 at a predetermined distance from the platen P and detachably with respect to the automatic document feeder F, and elevating means 24 for moving the platen cover 21 close to and away from the platen P. It has and.

The platen cover 21 has an engagement fixing portion 211 for engaging and fixing the platen cover 21 with respect to the support member 22, and a platen cover 21 for engaging with the support member 23.
The slide portion 212 that slides the platen P in a direction substantially parallel to the platen P, and an operator can grip the support members 22 and 23 and the platen cover 21 in order to release the engagement and fixation, and the support member 23. More Platen Cover 2
A U-shaped weight portion 213, which is provided on the downstream side of No. 1 and has a relatively large weight, is provided.

The supporting member 23 is fixed to the frame of the automatic document feeder F. The support member 22 is connected to the drive shaft 242 by a connecting member 241.

Next, the drive system of the document conveying section 10 and the platen cover section 20 and a part of the drive system of the separating / feeding section 40 will be described.

The output shaft 86 of the drive motor M2 is provided with an interrupter 871 formed by forming slits on a disk at equal intervals, and a photo is generated in response to light passing through the slit of the rotating interrupter 871. A pulse generator 87 including a sensor S4 is provided.

The transport belt 13 forming the transport path R2 is
The power from the drive motor M2 is transmitted to the belt drive transmission means 85.
The drive pulley 11 is rotated via the shafts 0, 851, the shaft 852, and the gears G8, G9, G10, so that the drive pulley 11 is driven in the forward direction (document conveying direction) and the backward feeding direction.

Further, the driven pulley 12 of the conveyor belt 13
The transfer roller 54 provided above the
The driving force is directly transmitted from the surface of the sheet discharge belt 51, and the paper discharge belt 51 is driven in the document transport direction at the same peripheral speed as the transport belt 13.

A registration roller 451 is fixed to the shaft 852, and is driven in the document transport direction at the same rotational angular velocity as the transport belt 13 but at a peripheral speed slightly slower than that of the transport belt 13.

That is, the registration roller 451 and the conveyor belt 13 are so constructed that the latter has a faster conveying speed than the former, and constitutes means for separating the preceding original document and the next original document.

Registration roller 451 and drive side pulley 1
1, the discharge belt 51 is one drive source (drive motor M2)
And the registration rollers 451 rotate at different peripheral surface speeds so that the registration roller 451 can convey the conveyance path R2 and the discharge passage R3 at a speed faster than the original fed in the feeding path R1. The rotary drive system described above can be controlled based on the clock signal of the pulse generating means 87.

On the other hand, the shaft 852 is driven by the gears G11, G.
It is transmitted to the drive shaft 242 via G12 and G13. The drive shaft 242 is gear-connected so as to rotate in the same direction as the pulley 11 that drives the conveyor belt 13, and slides the platen cover 21 in the same direction as the conveyance direction in which the conveyor belt 13 is reversed. When the transport belt 13 is driven in the forward direction (document transport direction), the platen cover 21 is held at the solid line position in FIG. 8, that is, the position close to the platen P by the forward rotation of the drive shaft 242. The platen cover 21 is provided by the torque limiter 853 incorporated in the shaft 852.
Is held at the solid line position in FIG. 8 with a constant force.

When the transport belt 13 is driven in the reverse feeding direction, the platen cover 21 is rotated by the reverse rotation of the drive shaft 242.
Is held at the position indicated by the chain line in FIG. 8, that is, at the position separated from the platen P.

Incidentally, the separating means for separating the preceding document and the next document to be fed, and further separating them, makes the peripheral speeds of the registration roller 451 of the feeding means and the conveyor belt 13 of the conveying means different from each other. In addition to the above configuration, in an embodiment, only the conveyor belt 13 which is the above-mentioned conveying means for performing the reverse feeding operation at a proper time and the discharging operation are executed,
It can also be configured by the paper discharge unit 50 that is the above-described paper discharge unit that does not rotate reversely with respect to the reverse feeding operation of the transport belt 13.

Further, a configuration example of the separating means is shown in FIGS.
7, respectively.

In the apparatus shown in FIG. 15, the separating means is basically composed of the conveying means and the paper discharging means as in the above, but in the apparatus 900 of this embodiment, the paper discharging section 910 is discharged. Along the paper path R3, there are an entrance roller 911, a pinch roller 912, a paper ejection first roller 913, a paper ejection second roller 914, and the like. The pulley 903 of the transport unit 910 and the first sheet discharge roller 913 are used as the second drive motor M2, and the second sheet discharge roller is used as the third drive motor M.
It is connected to 3. The first paper discharge roller 913 is coupled only via the one-way clutch ow (one-way rotation restricting means) so that it rotates only in the document discharge direction and does not rotate in the reverse feed direction. With such a configuration of the separating means, even if the preceding document comes into contact with the first and second rollers 913 and 914 at the same time, the document discharging operation is continuously executed and the sheet discharging is performed. The document is not damaged by the sliding contact of the first roller 913.

The apparatus 920 shown in FIG. 16 has almost the same configuration as that of FIG. 15, but prevents the preceding document from unnecessarily retreating when the preceding document is pulled by the next document to be separated. Therefore, the reverse feeding prevention means 931 such as a synthetic resin sheet is provided in the paper discharge path R3.

It is needless to say that the above-described reverse feeding prevention means 931 can be applied to the paper discharge path R3 of the paper discharge means 50 of the automatic document feeder F already described.

Further, in the device 900 having the configuration of FIG.
A torque limiter TL (torque limiting means) is provided between the drive motor M3 and the second sheet ejection roller, whereby the preceding document that is slidingly contacting the second sheet ejection roller and is being ejected is being fed backward. When the conveyance belt 902 pulls the next document to be conveyed to the conveyance path R2 side, the document is protected by a relatively small torque without a discharge operation.

Further, as in the apparatus 950 of FIG. 17, the belt roller 903 and the first discharge roller 91 of the discharge means 960.
3 and the discharge second roller 914 are respectively driven by separate drive motors M2 and M3, the discharge second roller is driven in the discharge direction, and the discharge first motor is driven in the reverse direction. The paper discharge first roller 91 in contact with the document to be sent
3 and the drive motor M3, a torque limiter TL is interposed to form a separating means.

According to the structure of the separating means, when the first sheet discharging roller comes into sliding contact with the preceding document being discharged,
Due to the action of the torque limiter TL, the reverse rotation of the first sheet ejection roller is stopped, and the original is prevented from being unnecessarily rubbed and damaged.

As shown in FIG. 18, the hinge portion 70 is composed of a hinge 71 with a spring for supporting the automatic document feeder F on the upper surface of the copying machine M so as to be openable and closable, and a hinge 72 without a spring.

<Operation> Next, the operation will be described.

When a document D is set on the document tray 31 and a copy command is given to the copying machine M prior to copying, the presence of the document D is confirmed by the empty sensor S1 and the document stopper 46 is placed below the guide plate 411. The document tray 3 is retracted and descends while the pickup roller 42 rotates.
The original D on 1 is touched. As a result, the document D is sent forward, enters between the feeding roller 43 and the separation belt 44, and the document D is advanced by the feeding roller 43 rotating in the transport direction. At this time, the separation belt 44 rotating in the reverse feeding direction prevents the lower original that contacts the separation belt 44 from advancing, and only one original is allowed to pass by the feeding roller 43.

The document D thus sent out is detected by the registration sensor S2 at its leading end, and then comes into contact with the registration roller 451 and the pinch roller 452 in the stopped state. After a lapse of a predetermined time from the detection of the leading edge of the document D, the rollers 42, 4
3. By stopping the belt 44, the document D is somewhat bent and the leading edge is uniformly pressed to the tangent portion of the registration roller 451 and the pinch roller 452, and the registration roller 451 and the pinch roller 451 which start to rotate after the document D contacts. The leading end of the roller 452 is drawn in parallel to the roller 452 and sent out.

The document D conveyed in the feeding path R1 as described above is guided to the entrance of the conveyance path R2 at the substantially center (point Y) of the reading section T of the platen P. Thus, the conveyor belt 13
The document D, which has entered the entrance of the conveyance path R2 formed between the platen P and the platen P, is sent forward along the conveyance path R2 by the conveyance belt 13 which is slightly faster than the registration roller 451.

At this time, the length of the document D in the carrying direction is judged by counting the pulse signals from the pulse generating means 87 from the time when the drive motor M2 is activated until the trailing edge of the carried document passes the registration sensor S2. it can. That is, at least the registration roller 451 and the conveyor belt 13 that are involved in the conveyance of the document D are synchronized with the pulse of the pulse generation means 87 and maintain the same conveyance speed, so that from the start of the drive motor M2 to the reading reference point X. The number of pulses can be recognized in advance, and when the registration sensor S2 detects the trailing edge of the document D while the leading edge of the document D is on the way from the point Y to the point X, the conveyed document is at least at the point X-.
It can be seen that it is less than or equal to the length between Y. That is, in this case, the document is determined to be the S size document.

When the original is an S-size original, the conveyor belt 13 is stopped after the pulse generation means 87 has counted a predetermined pulse (A pulse) after the rotation of the drive motor M2 is started. As a result, the document D can be stopped at the reading position in which the leading edge of the document is accurately aligned with the reference point X.

Next, it is judged whether or not the empty sensor S1 detects the original, and if the presence of the original D is not detected, the copying machine M is operated to execute copying. When copying is completed, the conveyor belt 13 and the paper discharge belt 51
Is operated to guide the document D to the paper discharge path R3, and the paper discharge tray 6
Discharge to 1.

When the empty sensor S1 detects a document, the drive motor M1 is started to drive the document tray 31.
Then, the next original document D is sent toward the registration roller 451 and the copying machine M is operated to perform copying.

When copying is completed, the drive belt M13 is stopped after the drive motor M2 is started and the pulse generation means 87 counts a predetermined pulse (A pulse). At this time, the leading edge of the first (first sheet) original is discharged to the paper discharge tray 61 with the rear end thereof being restrained by the paper discharge unit 50.

When the empty sensor S1 detects the document D to be copied on the document tray 31, the above-described operation is appropriately repeated, and the copied documents D are sequentially accumulated on the paper discharge tray 61.

Next, a case of handling an L-size document will be described with reference to FIGS. 13 and 14 (a) to (d).

From the start of the above-described document conveyance, the document D1 is advanced in the conveyance path R2 between the conveyance means 13 and the platen P.

If the document D1 moving forward on the conveyance path R2 passes the reading reference point X and the trailing edge of the document does not pass the registration sensor S2, the document D is judged to be an L size document. In this case, the conveyance of the document D1 is continued until the pulse generation means 87 counts a predetermined pulse (B pulse) after the trailing edge of the document passes the registration sensor S2.

When the trailing edge of the original reaches the entrance (point Y) of the conveyance path R2, the leading edge of the original D1 is conveyed to the upper surface of the paper ejection tray 61 through the paper ejection section 50, as shown in FIG. 13C. ing. Next, the transport belt 13 is rotated in the reverse direction, and the document D is fed backward along the upper surface of the platen P. As a result, the document D
1 enters between the platen P and the platen cover 21 between points YZ of the reading section T.

The original D1 is fed backward by the conveyor belt 13 until the leading edge of the original passes the reference point X of the reading section T by a predetermined amount. The switchback sensor S3 is used for backward feeding of the document D1.
Is controlled based on the detection signal of the trailing edge of the document (leading edge during forward feeding; left edge in the figure). That is, after the trailing edge of the document to be fed back passes the switchback sensor S3, the conveyance belt 13 is fed backward until the pulse generating means 87 counts a predetermined pulse (C pulse), and the trailing edge of the document D1 is the reading section. The transport belt 13 is stopped at the point W at the point T. (See FIG. 13D.) When the document is fed backward by the conveyor belt 13, the drive system of the platen cover 21 described above is simultaneously driven, and the platen cover 21 moves in a direction away from the platen P. .. As a result, the document D1 can enter between the platen P and the platen cover 21 between the points YZ of the reading unit T.

Thereafter, the original D1 is again conveyed by the conveying belt 13 in the forward direction, and when the rear end (left end) of the sequentially fed original D1 is located at the reference point X of the reading section T, the conveying belt 13 is stopped. . That is, after the pulse generator 87 counts a predetermined pulse (D pulse) that is overrun from the reference point X in the backward feeding, the feeding of the feeding belt 13 in the forward feeding direction is stopped. (See FIG. 14A.) As described above, when the document D1 is conveyed by the D pulse by the forward rotation of the conveyance belt 13, the platen cover 21 moves in the direction approaching the platen P. By this, the point Y-Z of the reading section T
The document D1 that has entered between the platen P and the platen cover 21 in between is pressed down to the platen P side. Copying is performed there.

During copying, when the empty sensor S1 detects no original on the original tray 31, the conveying belt 13 and the paper discharge belt 51 are driven in the forward feeding direction to move the original D.
1 is sent to the discharge tray 61 via the discharge path R3.

When the succeeding copy document D is detected by the empty sensor S1, the next document to be fed is advanced to the registration roller 451 as shown in FIG. 14A. Then, as shown in FIG. 14B, at the same time as the exposure is completed, the preceding original document D1 is also started to be conveyed together with the next original document D2 which has been previously fed to the registration roller 451.

When the conveyance is started, the linear velocity of the conveyor belt 13 is higher than the peripheral velocity of the registration roller 451, and at the same time, the preceding document D1 which is not restricted by the registration roller 451 while traveling along the conveyance path R2 is further advanced. Fast, both originals D
Documents D1 and D2 are gradually pulled apart, and the document D1 is quickly discharged from the paper discharge unit 50 to the paper discharge tray 61. (Fig. 1
4 (c) and (d)) On the other hand, the next document D2 is the above document D.
It is switched back as shown in FIG. 1 and is inserted under the platen cover 21 to be exposed.

While the preceding original document D1 and the next original document D2 are superposed and fed, the separating means for separating the two originals is a conveyor belt 13 which is the above-mentioned conveying means for performing a reverse feeding operation in a timely manner.
And a discharging unit 50 that is a discharging unit that performs only the discharging operation and does not rotate reversely with respect to the backward feeding operation of the conveyor belt 13.
In the case of the configuration constituted by, the conveyance belt 13
The discharging operation by is stopped, and only the next original document D2 that is in contact with the transport belt is separated and is fed backward.

The operation of the detaching means shown in FIGS. 15 to 17 showing various examples of the configuration has been described in the configuration description, and thus the description of the operation is omitted here.

By the way, when the original is fed from the registration rollers 451 and is longer than the expected passage time of the L size original, it is judged that the feeding is abnormal due to a jam or the like, and the second drive motor M2 is immediately driven. Stop.

On the other hand, for the first drive motor M1, as shown in FIG. 23, the drive motor M1 reversely rotates at the same time when a jam occurs,
By this reverse rotation, as described with reference to FIG. 4, the swing arm member 821 swings to raise the pickup roller 42, which is the feeding unit (step S11), and separates it from the document. Then, the timer is set at the same time (step S12), and the drive motor M is started for the first time when the timer is up.
1 is to stop (S13) and (S14). That is, at the time of feeding trouble, the pickup roller 42
Is designed to always return to the initial state.

When the suspension of the feeding is caused by the opening of the apparatus F, for example, the sensor S5 serves as a detecting means, the driving motor M2 is immediately stopped, and the pickup roller 42 of the pickup roller 42 is passed after the progress as shown in FIG. The ascending operation and the stopping operation of the drive motor M1 are executed.

<Modification> The feeding means in this embodiment is
Although it is a pickup roller in the document feeder F and the pickup roller is of a type pivotally supported by the end of the swing arm member 821, the present invention is not limited to such a configuration. Needless to say.

That is, even for the same pickup roller, for example, a non-circular rotating body having a peripheral surface formed of an arc portion and a non-arc portion (notch portion) without passing through a swing arm member, a so-called half-moon roller type. For example, when the power is normally turned on, the initial operation is performed, and the arc portion retracts from the guide plate surface of the sheet stacking portion due to the rotation of the rotating body, and the non-arc portion side is also buried under the surface of the guide plate and the May be in a non-contacting initial state, and the sheet may be drawn out at the arc portion when rotated. Further, the feeding operation is not necessarily limited to the feeding operation, and the feeding means may be in the middle of the feeding path.

According to the sheet feeding apparatus of the present invention, the feeding means for feeding the stacked sheets and the initial stage of separating the feeding means from the sheet every time the feeding means feeds the sheet. In a sheet feeding device having a driving means for driving a position and a feeding position for coming into contact with a sheet and feeding the sheet, a detecting means for detecting a feeding stop of the sheet by the feeding means, and this detecting means When the feeding suspension is detected, the control means for driving the driving means is provided at least while the feeding means is returned to the initial state, so that the feeding means can be operated even if the feeding operation is suddenly interrupted. The sheet can be separated from the sheet, the sheet is free from the feeding unit, the jam processing is not disturbed, the jam sheet can be quickly removed, and the sheet can be reset quickly. Further, it is not necessary to perform the initializing operation of the feeding means at the time of restart, and the restart can be promptly performed. Further, a feeding means for feeding the stacked sheets, an initial position where the feeding means is separated from the sheet every time the feeding means feeds the sheet, and a feeding position for feeding the sheet in contact with the sheet. In a sheet feeding device including a driving unit that drives the sheet feeding unit and a separating unit that separates the sheets fed by the feeding unit into one sheet, a detection unit that detects a sheet feeding stop by the feeding unit. And a control means for driving the driving means in a state where the separating operation by the separating means is stopped while the feeding means returns to the initial position at least when the detecting means detects the sheet feeding stop. Even if there is a sudden interruption of the feeding operation, the feeding means separates from the sheet to facilitate jam processing and sheet setting, and the separating means does not operate when the feeding means separates from the sheet. Jamushi for There is no damaging the door.

[Brief description of drawings]

FIG. 1 is a perspective view of an automatic document feeder to which a sheet feeding device of the present invention is applied.

FIG. 2 is a vertical sectional side view of the same automatic document feeder.

FIG. 3 is a plan view of the same automatic document feeder as above.

FIG. 4 is a plan view showing a drive system of a part of the separation feeding unit.

FIG. 5 is a plan view showing a drive system of part or all of a separation feeding unit, a document conveying unit, and a platen cover unit.

FIG. 6 is an explanatory view of a main part of a paper discharge unit.

FIG. 7 is a detailed structural diagram of a paper discharge section pulley.

FIG. 8 is a side view illustrating an outline of a platen cover part.

FIG. 9 is an example of an interlocking configuration of a document sub tray and a paper ejection sub tray.

FIG. 10 is another embodiment of the interlocking configuration of the original sub-tray and the paper output sub-tray

FIG. 11 is still another embodiment of the interlocking configuration of the original sub-tray and the paper output sub-tray.

FIG. 12 is an operation explanatory view of a device lacking a document sub tray and a paper discharge sub tray.

FIG. 13 is an explanatory diagram showing a feeding state of a large-sized document.

FIG. 14 is an explanatory diagram showing a feeding state of a large-sized document.

FIG. 15 is an embodiment showing the structure of the separating means.

FIG. 16 is another embodiment showing the structure of the separating means.

FIG. 17 is still another embodiment showing the structure of the separating means.

FIG. 18 is a perspective view showing a state where the automatic document feeder has released the platen.

FIG. 19 is an explanatory view of the state when the belt pulley is lifted and separated from the platen cover end portion.

FIG. 20 is an explanatory view of a state in which the belt pulley is lowered and brought into close contact with the end of the platen cover.

FIG. 21 is a structural explanatory view of a belt pulley vertical movement mechanism.

FIG. 22 is an explanatory view of main parts of a device lacking a belt pulley vertical movement mechanism.

FIG. 23 is a flowchart showing the behavior of the feeding unit and the driving unit when the sheet feeding is stopped due to a jam.

FIG. 24 is a flowchart showing the behavior of the feeding unit and the driving unit when the sheet feeding is stopped by opening the document feeding device.

[Explanation of symbols]

 F Automatic Document Feeder (Sheet Feeder) 40 Separation Feeder 42 Pickup Roller (Feeding Means) 43 Feeding Roller (Separating Means) 44 Separation Belt (Separating Means) S2 Registration Sensor (Detecting Means) 87 Pulse Generating Means (Detection means) S4 Photosensor (detection means) S5 Hinge part sensor (detection means) M1 First drive motor (drive means) (forward / reverse rotation motor)

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location G03G 15/00 112 7369-2H 15/04 119

Claims (4)

[Claims] 1. A feeding means for feeding stacked sheets,
In a sheet feeding device including a driving unit that drives the feeding unit to an initial position spaced from the sheet and a feeding position to feed the sheet every time the feeding unit feeds the sheet, Detecting means for detecting sheet feeding stop by the feeding means, and control for driving the driving means at least while the feeding means returns to the initial state when the detecting means detects sheet feeding stop And a sheet feeding device. 2. Feeding means for feeding stacked sheets,
Every time the feeding means feeds a sheet, the feeding means drives the feeding means to an initial position separated from the sheet and a feeding position to contact the sheet to feed the sheet, and the feeding means to feed the sheet. A sheet feeding device including a separating unit that separates the formed sheets into a single sheet, a detecting unit that detects a sheet feeding stop by the feeding unit, and a detecting unit that detects a sheet feeding stop. A sheet feeding device, comprising: a control unit that drives the driving unit in a state where the separating operation by the separating unit is stopped at least while the feeding unit returns to the initial position. 3. The drive means is a motor that rotates in the normal and reverse directions, and the feeding means contacts the uppermost sheet of the stacked sheets by rotation of the motor in a predetermined direction, and the sheet is driven by rotation of the motor in the reverse direction. The sheet feeding device according to claim 1, wherein the sheet feeding device is a rotating body that is separated from each other. 4. The driving means is a motor, and the feeding means has a peripheral surface formed by an arc portion and a non-arc portion, and a roller for feeding a stacked sheet that contacts the arc portion by rotation of the motor. The sheet feeding device according to claim 1 or 2, wherein