JPH0524693A - Sheet feeding device - Google Patents

Abstract

PURPOSE:To reduce the force necessary for the separation (release of press contact) between a separating member and a paper feeding member and permit the smooth operation in the separation. CONSTITUTION:A sheet feeding device is equipped with a supporting shaft 84 for supporting a separating member 44 in turnable manner, releasing member 511 which turns the separating member 44 around the supporting shaft 84 and separates a paper feeding member and the separating member 44, and a releasing shaft 510 which has the turning center on the nearly equal coordinates to the tuning center of the supporting shaft 84 relating to the plane which is nearly vertical to the supporting shaft 84 and supports the releasing member 511 in turnable manner.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copying machine, a printer,
The present invention relates to a sheet feeding device used in various devices such as a printing machine.

[0002]

2. Description of the Related Art In a sheet feeding device used in various devices such as a copying machine, a printer and a printing machine, a sheet feeding member feeds a sheet from a sheet supporting member, and then feeds the sheet in a conveying direction. It is widely practiced to reject and separate a sheet following one sheet to be conveyed by a member and a separating member that applies a force in the opposite direction to the sheet.

In this sheet feeding device, it is necessary to separate the sheet feeding member and the separating member (separating portion) in order to remove the jammed sheet.

Therefore, a supporting shaft for rotatably supporting the separating member (or the sheet feeding member), and a separating member (or a sheet feeding means) are rotated around the supporting shaft as a fulcrum to form the sheet feeding member and the separating member. There is known a pressure contact releasing device provided with a releasing member for partially separating the releasing members from each other and a releasing shaft for rotatably supporting the releasing member.

By the way, conventionally, a supporting shaft for supporting a separating member (or a sheet feeding member) is extended from the separating member in the left-right direction by the same length, and both ends thereof are supported by a frame of the apparatus. Therefore, the release shaft is provided with an axis line different from that of the support shaft (different rotation center).

In the above-mentioned conventional example, the releasing shaft and the supporting shaft have different centers of rotation. Therefore, the force transmitted from the release shaft to the separation member via the release member is
It is decomposed into a force in a direction of rotating the separating member and a force in a direction not useful for rotating the separating member with the support shaft as a fulcrum.

Since the force is lost as described above, there is a problem that a large force is required to rotate the pressure release shaft when releasing the pressure contact. On the other hand, since an excessive force acts on the separating member, there is a problem that the operation is not smooth.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a sheet feeding device in which the force required for separating (releasing pressure contact) between a separating member and a sheet feeding member is reduced and the operation during separation is smooth.

[0008]

To achieve the above object, the present invention provides a support shaft for rotatably supporting a sheet feeding member or a separating member, and a rotation of the sheet feeding member or the separating member with the supporting shaft as a fulcrum. A releasing member for moving the feeding member and the separating member away from each other, and a releasing member having a rotation center on the same coordinate as the rotation center of the supporting shaft with respect to a plane perpendicular to the supporting shaft. And a release shaft rotatably supported.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described with reference to the accompanying drawings with respect to an original conveying apparatus applied to a copying machine as an example.

A document feeder F is placed and mounted above the copying machine M shown in FIG. The document feeder F has a substantially square outer shape so that the document feeder F does not largely project to the left and right when viewed from the front of the copying machine M.

A platen P is provided in the upper part of the copying machine M, and a document feeder F placed so as to cover the platen P covers a certain area corresponding to approximately half of the platen P. The transport unit 10, the platen cover unit 20 that also covers the remaining area of the platen P, and the document set on the document tray unit 30 that is provided above the platen cover unit 20 are separately fed toward the platen P. Separation and feeding unit 40, paper discharge unit 50 that receives the exposed document conveyed by conveyance unit 10 and discharges it from platen P, and storage unit 6 that stores the document discharged by this paper discharge unit 50.
0, a hinge part 70 for supporting the document feeder F above the platen P of the copying machine M so as to be openable and closable, and a drive unit.
And a control unit 80.

FIG. 20 shows a state in which the document feeder F in FIG. 1 is released above the platen P, and the effective reading range (reading section T: length X-Z) is defined on the upper surface of the transparent platen P. Therefore, one end of the reading unit is determined as the reading reference point X. At the time of copying, by arranging one end of the manuscript D with this reference point X, a copy corresponding to the manuscript can be obtained.

The reading section T is the maximum size that can be copied, and is indicated by a chain line in the figure. For example, A3 size (297 mm x 420 mm) is the maximum size that can be copied, and here A3 size is a large size and A4 size (210 mm x 29 mm).
7mm) is assumed to be a small size. Therefore, the total length of the reading section T (between X and Z) is for large-sized originals, and half of that (X-
(Between Y) is for small size originals. In FIG. 20, the small-sized document D is positioned on the reading unit T in accordance with the reference point.

In FIG. 2, two drive motors M1 and M2 provided in the document feeder F and sensors S1 to S for collecting information necessary to control the operation of the document feeder F.
5 and control board 89 are shown.

The drive motor M1 is drivingly connected to the separating / feeding unit 40, and is driven and controlled mainly based on output signals from the sensors S1 and S5.

The drive motor M2 is drivingly connected to the carrying section 10 and is driven and controlled mainly based on output signals from the sensors S2, S3 and S4.

The sensor S1 is an empty sensor for detecting the presence / absence of a document set on the document tray section 30.

The sensor S2 is provided on the way of the conveying path for conveying the originals separated by the separating / feeding unit 40 to the platen P, and detects the leading edge or the trailing edge of the original passing through the conveying path. It is a sensor.

The sensor S3 is a switchback sensor for detecting the leading edge or trailing edge of the document conveyed in the paper discharge section 50.

The sensor S4 is an output shaft 8 of the drive motor M2.
6 is a photo sensor that detects the amount of rotation of an interrupter 871 (described later) provided in FIG.

The sensor S5 is provided on the hinge portion 70, and the original document feeding device F with respect to the copying machine M has a platen P.
It is detected whether the upper state of the platen P is in the open state or the upper side of the platen P is in the closed state as shown in FIG.

Further, the accommodating portion 60 as the second supporting means for accommodating the copied document is provided with a projecting member 62 extending in a direction substantially parallel to the document transport direction. The projecting member 62 is provided to allow the original stored in the storage section 60 to sit down, and the original stored in the storage section 6 can be accommodated.
If it is longer than 0, the tip will protrude from the storage 60,
This is to prevent the leading edge of the protruding document from hanging above the document tray section 30.

Next, the document feeder F will be described in detail with reference to FIGS.

As shown in FIGS. 3 and 4, the document feeder F
Is a document tray unit 3 for stacking documents from the upstream (right side in FIG. 3) to the downstream (left side) in the document transport direction.
0, a separation feeding unit 40 as a separating unit that separates and conveys the original on the tray into one sheet, and the separation feeding unit 40.
A document transport unit 10 is provided for receiving a document transported by and transporting the document further downstream.

A platen cover 20 is provided below the separating / feeding unit 40 on the platen P side, and a document received from the document transporting unit 10 is provided on the front and back sides above the document transporting unit 10. Paper output section 5 that conveys paper while reversing it
0 is provided. Above the separating / feeding unit 40 and the document transport unit 10, a storage unit 60 for storing the document transported by the paper discharge unit 50 is provided.

In the document feeder F, the document tray section 30
Is a loading tray 3 as a sheet supporting member for loading a document.
1 and a pair of side edge guides 32L and 32R that regulate the side edges of the document set on the tray 31 and the auxiliary tray 33. The side edge guides 32L and 32R move in the width direction of the document (vertical direction in FIG. 4) along the guide guide 321. A rack and pinion mechanism (not shown) is connected to the side edge guides 32L and 32R, and the central portion of the original set on the loading tray 31 is positioned at the reference line K shown in FIG.

The auxiliary tray 33 is rotatably attached to the placing tray 31 by a rotating shaft 331, and stably supports the rear end side of a large-sized document placed on the placing tray 31.

The separating / feeding section 40 is provided with an original conveying path R1 for guiding the separated original from the predetermined position of the platen P (the center Y point of the reading section T) to the platen P. R1 is partitioned by the guide plates 410 and 411. Then, the separating / feeding unit is arranged along the document conveyance path R1. That is, a pickup roller 42 as a feeding member is provided at the entrance side of the conveyance path R1 so as to be able to move forward and backward in the mounting tray 31, and a feed roller 43 as a paper feed member and a separation belt as a separation member from each guide plate 410, 411. 44 are arranged so as to enter the transport path R1 and not to contact each other, and to overlap each other.
Further, a registration roller 451 as a first registration member and a pinch roller 452 as a second registration member are provided facing each other on the exit side of the transport path R1.

The exit portion of the transport path R1 is located substantially at the center (point Y) of the reading section T defined on the upper surface of the platen P.

At the entrance of the transport path R1, the presence or absence of the original on the loading tray 31 in cooperation with the original stopper 46 provided so as to be able to move forward and backward with respect to the guide plate 411 and the sensor S1 (see FIG. 2). A lever 47 is provided to detect the error, and a sensor S2 is provided between the paper feed roller 43 and the registration roller 451 on the conveyance path R1. The document stopper 46, the pickup roller 42, the paper feed roller 43, and the separation belt 44 provided along the transport path R1 are shown in FIGS.
As shown in 0, the power from the motor M1 is rotated in a predetermined direction via the belt drive transmission means 810, 811 and the plurality of gears G.
It is configured to rotate.

Assuming that one original is pulled out from the loading tray 31 and sent to the transport path R1, the motor M
1 rotation (normal rotation) is transmitted to the shaft 831 via the gears G2, G3, G4, and the rotation of the shaft 831 drives the drive transmission member 832 to rotate the shaft 833 in a predetermined direction.

At this time, since the document stopper 46 moves to the position shown by the chain line in FIG. 3, the document on the loading tray 31 can be separated and fed. When the document stopper 46 rotates (falls) and abuts on a stopper (not shown), the spring clutch 834 prevents the shaft 833 of the document stopper 46 from being driven with a certain driving force or more.

The pickup roller 42 has a shaft 82 for holding the paper feed roller 43 by means of a swing arm member 821.
Since it is pivotally supported on the shaft 8, the rotation of the lever 836 that is fixed to the shaft 831 and comes into contact with the swing arm member 821 causes the swing arm member 821 to rotate downward toward the document, and Contact the surface. When the pickup roller 42 comes into contact with the document, the contact pressure of the pickup roller 42 with respect to the document is maintained constant by the spring clutch 834.

Further, the normal rotation of the motor M1 is determined by the gears G1, G5, G
It is transmitted to the shafts 82 and 84 via 6, G7, and the paper feed roller 43
And the separation belt 44 are rotated 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 paper feed roller 43 advances the document. It is adapted to rotate.

Further, the one-way clutch 823 is also incorporated in the gear G6, and even if the rotation of the gear G5 is stopped, when the original is forcibly conveyed forward, the separation belt 44 follows the forward movement of the original. It is designed to rotate.

The gear G1 has a built-in one-way clutch 824. When the motor M1 rotates in the reverse direction, the gear G1 idles, and the drive is not transmitted to the rollers 42, 43 and the separation belt 44, but the document stopper 46 and the lever Drive is transmitted to 836, and the motor M1 is rotationally driven in a direction opposite to that when the motor M1 is normally rotated.

Further, the shaft 838 is provided with a spring clutch 837, and when the motor M1 reversely rotates, the document stopper 4 is inserted.
6 and the lever 836 are prevented from being driven upward by a predetermined force or more.

With the structure of the separating and feeding section 40 described above,
When the motor M1 rotates in the normal direction, only the pickup roller 42 and the paper feed roller 43 rotate in the forward direction (original conveying direction),
The separation belt 44 rotates in the reverse feeding direction. As a result, the documents placed on the loading tray 31 are conveyed one by one from the entrance to the exit of the conveyance path R1.

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

The document conveying section 10 comprises 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 a plurality of press rollers 14 for pressing the conveying belt 13 against the platen P. Become. Further, the document transport unit 10 has approximately half (X) of the maximum copy document size (reading unit T) on the upper surface of the platen P on the reading reference point X side.
(Between Y and Y).

A conveyor belt 13 is provided at the exit of the conveyor path R1. The conveyance belt 13 forms a document path R2 between itself and the platen P, and the entrance of the document path R2 is at the center of the reading unit T (Y
Point), and the exit is located substantially at the reading reference point X defined at the front end of the reading section T.

By this document transport section 10, the document discharged from the exit of the transport path R1 is transported to the reference point X of the reading section T, or is transported in front of the reference point X and is discharged. Can be transported in the opposite direction.

As shown in FIGS. 3 and 7, the original feeding section 10
Behind the exit (reference point X) of the above, a paper discharge section 50 is provided in series with the document conveying section 10. The paper discharge unit 50 is
An endless belt-shaped paper discharge belt 51, a pair of pulleys 52 and 53 that drive the paper discharge belt 51 so as to be able to rotate forward and backward, and a rolling roller 5 that transmits the drive of the conveyor belt 13 to the pulley 53.
4 and the document discharged from the exit of the document path R2 in the storage section 60
Has guide members 55 and 56 for guiding to
A discharge path R3 for guiding the document sent out from the document transport unit 10 is formed between 5 and 56.

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 rolling contact roller 54 is biased directly by a spring member (not shown) on the surface of the conveyor belt 13 at a position facing the driven pulley 12, and the fourth and seventh rollers are provided.
As shown in the figure, they are in contact with each other at substantially the center of the conveyor belt 13.

Further, the discharge belt 51 and the pair of pulleys 5
2, 53 and the rolling contact roller 54 are integrally supported by the pair of left and right side plates 58 and can be fixed to the outer cover of the transporting device F as a unit, which facilitates assembly.

In this embodiment, the document discharged from the document path R2 between the conveyor belt 13 and the platen P is introduced into the paper discharge path R3 and conveyed to the storage section 60.

The storage section 60 includes a storage tray 61 and a projecting member 62 extending in a direction substantially parallel to the document transport direction.
It consists of Since the storage tray 61 is disposed above the loading tray 31, the copying machine F is provided with the original document D to be separated and fed and the copied original document D1 overlap each other as shown in FIG. Placed above the platen of
It is stored. In other words, it is possible to configure a document feeder that is small and lightweight, and that the size of the document to be transported is not particularly limited, and that the processed document can be easily handled.

Referring to FIGS. 3, 8 and 9, the platen cover section 20 is provided below the separating / feeding section 40 on the platen P side, and is provided in parallel with the platen P. Support members 22 and 23 that support the cover 21 with the platen P at a predetermined interval and are detachably attached to the document feeder F, and the platen cover 21.
And an elevating means 24 for bringing the platen P close to and away from the platen P.

The platen cover 21 has an engaging and fixing portion for engaging and fixing the platen cover 21 to the support member 22.
211, a slide portion 212 that engages with the support member 23 and slides the platen cover 21 in a direction substantially parallel to the platen P, and releases the engagement / fixation between the support members 22 and 23 and the platen cover 21. For this reason, an operator-gripable weight portion 213, which is provided downstream of the support member 23 in the sliding direction of the platen cover 21 and has a relatively large weight, is provided.

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

In FIG. 9, the platen cover 21 is attached to the support member 2
2 and 23 are removed. Although the drawing shows the document feeder F closing (covering) the platen P of the copying machine M, the platen cover 21 is normally removed by the document feeder F above the platen P. The separation belt 44 and other mechanisms provided in the separation feeding unit 40 can be easily maintained.

The platen cover portion 20 is an area on the upper surface of the platen P other than the area covered by the document conveying portion 10, that is, approximately half (between Y and Z) on the opposite side of the reading reference point X of the reading portion T. It has a size to cover.

With reference to FIGS. 6, 7 and 11, the original conveying section 1
0, the drive system of the platen cover unit 20 and the separate feeding unit 40
A part of the drive system will be described.

The output shaft 86 of the motor M2 is provided with an interrupter 871 formed by forming slits on a disk at equal intervals, and a photosensor for generating a pulse in response to light passing through the slit of the rotating interrupter 871. A pulse generator 87 composed of S2 is provided.

The conveyor belt 13 forming the document path R2 receives the power from the motor M2 as belt drive transmission means 850, 851 and the shaft 8
The drive side pulley 11 is rotated via the gears 52 and the gears G8, G9, G10 so that the drive side 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 rolling roller 54 provided above the
The driving force is directly transmitted from the surface of the delivery belt 51, and the delivery belt 51 is driven at the same peripheral speed as that of the transport belt 13 in the same document transport direction.

A registration roller 451 is fixed to the shaft 852, and is driven in the same document conveying direction at the same peripheral speed as the conveying belt 13.

That is, the registration roller 451, the driving pulley 11, and the paper discharge belt 51 are one driving source (motor M2).
And the registration roller 451 rotates at a substantially equal peripheral surface speed so that the registration roller 451 can convey the original document path R2 and the paper discharge path R3 at the same speed as the original document sent through the conveyance path R1. That is,
The originals transported through the passages R1, R2, R3 are
It is designed to move at a constant speed. 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 drive of the shaft 852 is driven by the gears G11 and G.
It is transmitted to the drive shaft 242 via 12, G13. The drive shaft 242 is
It 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 forward and reverse conveying directions of the conveyor belt 13. When the transport belt 13 is driven in the forward direction (document transport direction), the platen cover 21 is held at the position indicated by the solid line in FIG. Torque limiter 8 built into shaft 852
By 53, the platen cover 21 is held at the position indicated by the solid line in FIG. 8 with a constant force.

When the conveyor belt 13 is driven in the reverse feeding direction, the platen cover 21 is held at the position indicated by the chain line in FIG. 8, that is, the position separated from the platen P by the reverse rotation of the drive shaft 242. The platen cover 21 is held at the position indicated by the chain line in FIG. 8 with a constant force by the torque limiter 854 incorporated in the shaft 242.

Referring to FIGS. 3 to 6 with reference to FIGS. 21 and 22, the drive side shaft 84 and the driven side shaft 500 of the separation belt 44 are integrally supported by the holder 501. A shaft 84 as a support shaft supports the separation belt 44 so as to be vertically rotatable about the shaft 84. Then, the biasing leaf spring 502 biases the separation belt 44 through the holder 501 in a direction in which the separation belt 44 is constantly in pressure contact with the sheet feeding roller 43.

Further, the pinch roller 451 is vertically rotatable about a fulcrum 505 by a holder 504 holding a shaft 503 thereof. Then, the biasing leaf spring 506 causes the pinch roller 4
52 is constantly urged in the direction of being pressed against the registration roller 451. As described above, the registration roller 451 and the pinch roller 452 form a pair of registration members.

A release button 507, which is pressed to remove the jammed sheet of the separating / feeding unit 40, is provided as shown in FIGS. 2 and 4. The release button 507 rotates the release shaft 510 via links 508 and 509 as shown in FIG. With the rotation of release shaft 510, release shaft 5
The release member 511 provided on the holder 10 is used for the holder 501 of the separation belt 44.
Is pressed against the biasing leaf spring 502.
As a result, the separation belt 44 rotates about the shaft 84 as a fulcrum in a direction in which the separation belt 44 is separated from the paper feed roller 43. In addition, the rotating separation belt 44 causes the holder 504 to rotate against the biasing plate spring 506, causing the pinch roller 452 to rotate.
Separate from 51. The holder 504 serves as a second releasing member that separates the resist portion in association with the separating movement of the separating portion.

One end of each of the shaft 84 and the release shaft 510 is supported on the frame side of the document feeder F and a bracket is provided.
It is supported by 512 and 513. The release shaft 510 is provided so as to have its rotation center on the substantially same coordinate as the rotation center of the shaft 84 with respect to the plane perpendicular to the shaft 84. Therefore, all the forces transmitted from the release shaft 510 to the separation belt 44 act in the direction of rotating the separation belt 44,
The force required to separate the separating portion and the resist portion can be reduced. Further, since the force other than the direction of rotating the separation belt 44 does not act, the operation of the mechanism at the time of separation can be made smooth.

Hinge portion 70 shown in FIGS.
Is composed of a hinge 71 with a spring that supports the 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.

The spring hinge 71 includes a main body fixing portion 711 fixed to the copying machine M side, an attached fixing portion 712 fixed to the conveying device F side, a pin 713 connecting both portions 711 and 712, and both portions 7.
Spring means 7 for urging 11,712 in the opening direction around the pin 713
It is composed of 14 and.

Further, it is provided at a position slightly upstream (right side in the figure) from the central portion of the apparatus F with respect to the document conveying direction of the document conveying apparatus F (horizontal direction in FIG. 4). This hinge position corresponds to the positions of the motors M1 and M2 and the motors M1 and M.
The position of the center of gravity shifted from the position of the rotary drive system or the like connected to 2 to the upstream side in the transport direction of the apparatus F is approximately corresponded.

The springless hinge 72 comprises a support member 721 fixed to the copying machine M side, a concave support portion 722 provided in the document feeder F, and a pin 723 connecting both members 721, 722.
The hinge 72 is provided at a position downstream (on the left side in FIG. 4) of the document transport device F in the document transport direction, and includes a support member 721 fixed to the copying machine M and a concave support portion 722 of the frame cover of the document transport device F. It is rotatably connected by a pin 723.

The operation of the document feeding device F having the above structure will be described below.

FIGS. 12 and 13 (A) to 13 (C) show the case of handling a relatively small size original such as A4 to letter size horizontal.

FIG. 12A shows a state in which the document D is set on the placing tray 31 prior to copying, and when a copy command is given to the copying machine M, the presence of the document D is confirmed by the empty sensor S1. , The document stopper 46 is the guide plate 41
1, the pickup roller 42 rotates and descends to come into contact with the document D on the tray 31. As a result, the document D is sent forward and the paper feed roller 43
The document D is moved forward by the sheet feeding roller 43 which is inserted between the separation belt 44 and the separating belt 44 and rotates in the conveying direction. This time,
When a plurality of documents D are placed on the loading tray 31 as shown in FIG. 12B, and a plurality of documents are simultaneously sent by the pickup roller 42, the separation belt 44 is rotated in the reverse feeding direction by the separation belt 44. The lower document, which contacts 44, is prevented from advancing. Therefore, only one original is allowed to pass forward by the paper feed roller 43.

In this way, the fed document D is contacted with the registration roller 451 and the pinch roller 452 in the stopped state after the leading edge of the document is detected by the registration sensor S2. Document D
By stopping the rollers 42, 43 and the belt 44 after a lapse of a predetermined time from the detection of the leading edge of the document, the document D is bent to some extent, and the leading edge is evenly distributed between the registration roller 451 and the pinch roller 452.
It is pressed against the tangent part of. As a result, the registration roller 451 and the pinch roller which start rotating after the document D contacts
The tip is drawn in parallel with the 452 and sent out forward. (Skew correction action) As described above, the transport path R1
The document D conveyed through is conveyed to the entrance of the document path R2 at the substantially center (point Y) of the reading section T of the platen P. The document D that has entered the entrance of the document path R2 formed between the transport belt 13 and the platen P in this way is sent forward along the document path R2 by the transport belt 13 that is driven in synchronization with the registration rollers 451.

At this time, the length of the document D in the carrying direction can be determined by counting the pulse signals from the pulse generating means 87 from the time when the motor M2 is activated until the trailing edge of the carried document passes the registration sensor S2. . That is, at least the registration roller 45 that is involved in the conveyance of the document D.
Since the conveyor belt 13 is synchronized with the pulse of the pulse generating means 87 and maintains the same conveyor speed, the motor M2
It is possible to previously recognize the number of pulses from the start of the process until the reading reference point X is reached, and the registration sensor S2 detects the rear end of the document D when the leading edge of the document D is on the way from point Y to point X. Then, it can be seen that the conveyed document is at least the length between points X and Y. That is, in this case, it is determined that the document is small. (See FIG. 16) When the original is small in size as shown in FIG. 17, the motor M is used.
After starting the rotation of 2, the pulse generating means 87 counts a predetermined pulse (A pulse) and then stops the conveyor belt 13. 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, as shown in FIG.

Next, it is judged whether or not the empty sensor S1 detects the original, and when the presence of the original D is not detected, the copying machine M is operated to execute copying. When copying is completed, the conveyance belt 13 and the paper discharge belt 51 are operated to guide the document D to the paper discharge path R3 and discharge it to the storage tray 61.

When the empty sensor S1 detects a document, the motor M1 is activated to feed the next document D from the loading tray 31 toward the registration rollers 451 and the copying machine M is operated to make a copy. Run. (Fig. 13
(Refer to (A)) When the copying is completed, the conveyor belt 13 is stopped after the pulse generation means 87 has counted a predetermined pulse (A pulse) from the start of the motor M2. At this time, the leading edge of the first (first) document is discharged to the storage tray 61 with the rear end thereof being restrained by the paper discharge unit 50. (Fig. 1
3 (B)) The empty tray S1 with the empty sensor S1
When the original document D to be copied is detected, the above-described operation is appropriately repeated, and the copied original documents D are sequentially accumulated in the storage tray 61 as shown in FIG.

14 and 15 (A) to 15 (D) show the case of handling a large-sized original document longer than the X-Y interval on the platen P defining a relatively small-sized area.

Start of conveyance of the above-mentioned document (FIG. 12 (A))
Subsequently, the document D is moved forward along the document path R2 between the conveying means 13 and the platen P.

As shown in FIGS. 16 and 18, if the document D advancing along the document 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 large. . In this case, the trailing edge of the original is the registration sensor S.
2, the pulse generation means 87 causes the predetermined pulse (B
The document D is continuously conveyed until the number of pulses is counted.

When the trailing edge of the document reaches the entrance (point Y) of the document path R2, the leading edge of the document D passes through the paper discharge section 50 and is conveyed to the upper surface of the storage tray 61 as shown in FIG. 14C. There is.

Next, the conveyance belt 13 is rotated in the reverse direction to make the original D.
Are fed back along the upper surface of the platen P. This allows
The document D enters between the platen P and the platen cover 21 between points YZ of the reading unit T.

The document D is fed backward by the conveyor belt 13 until the leading edge of the document passes the reference point A of the reading section T by a predetermined amount. The backward feeding of the document D is controlled based on the detection signal of the trailing edge of the document (the leading edge during forward feeding; left side in the figure) of the switchback sensor S3. In other words, after the trailing edge of the document to be fed back passes the switchback sensor S3, the conveying belt 13 is fed backward until the pulse generating means 87 counts a predetermined pulse (C pulse), and the trailing edge of the document is read by the reading section T. The conveyor belt 13 is stopped at the point W. (Fig. 1
4 (D)) The conveying belt 13 keeps the original document until the pulse generator 87 counts a predetermined pulse (B pulse) after the rear end of the original document (the rear end at the time of forward feeding; the right side in the figure) passes the registration sensor S2. When the document D is conveyed, the leading edge of the document is always detected by the switchback sensor S3.
The switchback sensor S3 is arranged near the downstream side of the platen P in the forward feeding direction in consideration of the size of the used document.

When the document is fed back 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. This makes it easier for the document D to enter between the platen P and the platen cover 21 between the points Y and Z of the reading unit T.

Thereafter, the document D is conveyed again in the forward direction by the conveyor belt 13, and the trailing end of the document D fed in the forward direction is read by the reading portion T.
When it is located at the reference point X, the conveyor belt 13 is stopped. That is, after the pulse generator 87 counts a predetermined pulse (D pulse) that has 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. 15A) As described above, the conveyor belt 1
When the document D is conveyed by D pulses in the forward rotation of 3, the platen cover 21 moves in a direction in which the platen P approaches the platen P. As a result, the document D that has entered between the platen P between the points Y and Z of the reading unit T and the platen cover 21 is pressed toward the platen P side. Then, copy is executed.

After the completion of copying, if the empty sensor S1 does not detect a document on the tray 31, the transport belt 13 and the paper discharge belt 51 are driven in the forward feeding direction to store the document D through the paper discharge path R3. Send it to the tray 61.

When the succeeding copy document D is detected by the empty sensor S1, the motor M2 is driven by a predetermined pulse (E pulse) according to the size of the document to be copied, as shown in FIG. 15B. The trailing edge of the document (the trailing edge at the time of forward feeding) is conveyed to the approximate center of the reading section T (point Y) by the forward feeding of the paper discharge belt 13.

Next, the next document is conveyed to the position of the registration roller 451 by the above-described document separating and feeding operation.
(FIG. 15 (C)) Here, the motor M2 is activated to rotationally drive the registration roller 451, the conveyance belt 13, and the paper discharge belt 51 at the same time. As a result, the copied document D1 is sent to the storage tray 61 and the succeeding document D2 is sent.
Moves forward along the conveyance path R1 toward the point Y of the reading unit T, and as described above, the document D is sequentially fed by the conveyance belt 13 until the trailing edge of the document is located at the point Y of the reading unit T. (Fig. 15
(D) According to the document feeder F having the above-described configuration, a large-sized document (a document of a large size can be obtained by a small-sized document feeding system of a relatively small size, which is about half the size of the reading unit T on the platen P (X-Y size) or less. It is possible to effectively carry out the transfer process even in the (X-Z size), and it is possible to rationalize the system, reduce the cost of the device, and reduce the size and weight.

In the above embodiment, about twice the small size is set as the large size. Needless to say, even if the large size (between X and Z) is made larger than twice the small size (between XY), Alternatively, even if it is small, it is substantially possible.

[0089]

According to the present invention described above, the supporting shaft for rotatably supporting the sheet feeding member or the separating member, and the sheet feeding member or the separating member are rotated about the supporting shaft as a fulcrum to separate them from the sheet feeding member. A releasing member for separating the member from each other, and a releasing shaft for rotatably supporting the releasing member, which has the turning center on the same coordinate as the turning center of the supporting shaft with respect to a plane perpendicular to the supporting shaft. Since all the forces transmitted from the release shaft to the sheet feeding member or the separating member act in the direction of rotating the sheet feeding member or the separating member, the force necessary for separating the sheet feeding member and the separating member is provided. Can be made smaller. Further, since the force other than the direction of rotating the sheet feeding member or the separating member does not act, the operation of the mechanism at the time of separation can be made smooth.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment in which a document feeder according to the present invention is applied to a copying machine.

FIG. 2 is a perspective view showing an embodiment showing a partial internal structure of the same document feeder.

FIG. 3 is a side sectional view of the same document feeder.

FIG. 4 is a plan view of the same document feeder.

FIG. 5 is a plan view showing a drive system of a part of the separation supply unit.

FIG. 6 is a plan view showing a drive system of part or all of a separation / feed unit, a document conveyance unit, and a platen cover unit.

FIG. 7 is a perspective view illustrating a main configuration of a paper discharge unit.

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

FIG. 9 is a side view illustrating the outline of attachment and detachment of the platen cover.

FIG. 10 is a side view showing a drive system of a part of the separation supply unit.

FIG. 11 is a side view showing a drive system of part or all of a separation / feed unit, a document conveyance unit, and a platen cover unit.

FIG. 12 is an explanatory diagram showing a feeding state of a small-sized document.

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

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

FIG. 15 is an explanatory diagram showing a feeding state of a large-sized document.

FIG. 16 is a flowchart illustrating a separating / conveying operation of the document conveying device.

FIG. 17 is a flowchart for explaining a conveyance / paper discharge operation of a small-sized document.

FIG. 18 is a flowchart illustrating the operation of conveying and discharging a large-sized document.

FIG. 19 is a side view illustrating the outline of a hinge portion.

FIG. 20 is a perspective view showing an embodiment in which a document feeder according to the present invention is applied to a copying machine with a platen released.

FIG. 21 is a plan view showing a pressure contact release mechanism for the separation section and the resist section.

FIG. 22 is a vertical cross-sectional view showing a press-contact releasing mechanism for the separating portion and the resist portion.

[Explanation of symbols]

M copier F Document feeder P Platen D manuscript (sheet) 10 Document feeder 20 Platen cover part 30 Document tray section 31 Loading tray (sheet support member) 40 Separate feeding section 42 Pickup roller (feeding member) 43 paper feed roller (paper feed member) 50 paper output section 60 storage 70 Hinge part 84 shaft (support shaft) 451 Registration roller (Registration member) 452 Pinch roller (resist member) 510 release axis 511 Release member 504 Holder (second releasing member)

Claims (3)

[Claims] 1. A sheet feeding member for feeding a sheet stacked on a sheet supporting means in the conveying direction, and a sheet feeding member which is provided in contact with or close to the sheet feeding member and exerts a force in a direction opposite to the sheet feeding member to the sheet. In a sheet feeding device provided with a separating member for giving, a supporting shaft for rotatably supporting the paper feeding member or the separating member, and rotating the paper feeding member or the separating member with the supporting shaft as a fulcrum. A releasing member that separates the sheet feeding member and the separating member from each other; and a rotation center of the support shaft on a plane substantially perpendicular to the support shaft on a coordinate substantially the same as the rotation center of the support shaft, A sheet feeding device, comprising: a release shaft that rotatably supports a release member. 2. A sheet supporting member on which sheets are stacked, a feeding member for feeding the sheet from the sheet supporting means, a sheet feeding member for feeding the sheet fed by the feeding member in the conveying direction, and a contact member for the sheet feeding member. Alternatively, a separating member that is provided close to each other and applies a force in a direction opposite to that of the sheet feeding member to the sheet, and a pair of resists provided on the downstream side of the sheet feeding member and the separating member in the sheet conveying direction and in pressure contact with each other. In a sheet feeding device including a member, a support shaft that rotatably supports the paper feed member or the separation member, and the paper feed member or the separation member are rotated about the support shaft as a fulcrum, A release member for separating the sheet feeding member and the separating member from each other, and a release shaft having a rotation center substantially the same as the support shaft and rotatably supporting the release member. Sheet feeder. 3. A second member for separating the pair of resist members from each other in association with the separation of the sheet feeding member and the separating member.
3. The sheet feeding device according to claim 2, further comprising: