JPH0511536A - Document feeder for image forming device - Google Patents

Abstract

PURPOSE:To provide a document feeder which automatically feeds a document having a comparatively small size whose frequency in use is high and a document having a size larger than the above size, and which is made small in size and light in weight. CONSTITUTION:This feeder is provided with a separating means 40 which is installed above a platen P and separates and feeds the documents one by one, a guiding means which guides the document fed from the separating means 40 from a specified position on the platen P to the platen, a carrying means 10 which covers from the specified position on the platen P to one end of the platen P, and a platen cover installed just under the separating means 40.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document feeding device for automatically feeding a document to an image reading position of an image processing device such as a copying machine, and more specifically, for automatically feeding a document of a relatively small size. The present invention relates to a document feeder that can automatically convey even large-sized originals and efficiently convey originals in accordance with originals of different sizes.

2. Description of the Related Art In an image processing apparatus such as a copying machine M, an original having an image to be read is placed on a platen of the apparatus.
A device that automatically conveys the document to the (document reading unit) is widely used. In the copying machine M, for example, A3 size (297 mm x 420 m
m), and those that can handle larger-sized manuscripts tend to become mainstream for office work. In a copying machine for copying such large size barge, at least a platen having an area corresponding to the maximum target original size is provided,
The belt-shaped endless belt for conveying originals having a size corresponding to this also becomes large and heavy.

Further, it is unreasonable to automatically feed a small-sized original as well as a large-sized original. In other words, in a transport system designed for a document of the maximum size (for example, A3) that can be copied, A which is generally highly used is used.
It can be said that the efficiency of the transport system is low, because the 4 size original is also transported on the platen similarly to the A3 size original. Therefore, it is ideal that a compact system for transporting a small-sized document can automatically transport a document larger than the design size.

[0003]

[Patent Document 1] Japanese Patent Laid-Open No. 2-158728 proposes a document feeder for the purpose of rationally conveying documents of different sizes. This conventional apparatus automatically conveys both small-sized originals that are frequently used and large-sized originals that are rarely used. However, it cannot be said that an increase in size of the original conveying system is avoided, and the intended reduction in size of the original conveying apparatus is not satisfied.

In order to solve the above-mentioned conventional problems, the objects of claims 1 and 2 are to be able to automatically convey relatively small-sized originals which are frequently used and originals of larger sizes, and
An object of the present invention is to provide a compact and lightweight document feeder.

A third aspect of the present invention is a compact conveying device designed to automatically convey a relatively small size document that is frequently used, and a document conveying device that can effectively automatically convey a larger size document. To provide.

[0006]

In order to achieve the above object, the document feeder of claim 1 is provided above a platen for separating the documents supported by the supporting means for supporting the documents one by one. Separation means, guide means for guiding the document sent forward from the separation means in the conveying direction to a platen from a predetermined position on the platen, and one end of the platen from the predetermined position on the platen to be guided by the guide means. Transporting means for reversibly transporting the original document to one end side or the other end side of the platen, and covering and transporting a part of the platen other than the one covered by the transporting means. And a platen cover provided directly below the separating means for forming an entrance space for a document conveyed by the means between the platen and the platen.

According to another aspect of the document feeder of the present invention, the document is placed substantially horizontally and is supported by the first support means for supporting at least the tip of the placed document above the platen, and the support means. Separating means provided above the platen for separating the originals one by one, and first guide means for guiding the originals sent forward from the separating means in the conveying direction from a predetermined position on the platen to the platen. A transport means for reversibly transporting the document guided by the guide means to one end side or the other end side of the platen, covering one end side of the platen from a predetermined position on the platen and the transport means on the platen. Is provided to cover a part of the platen other than the part covered by the conveying means, and forms an entrance space for an original conveyed by the conveying means between the platen and the platen.
A platen cover provided directly below the separating means and a second end which is connected to one end side of the conveying means and guides the original sent from the conveying means to the upper side of the platen while reversing the original.
Of the guide means, the separating means, the first guide means, and the conveying means, and the document guided by the second guide means is supported in a substantially horizontal state by the first supporting means. Second supporting means for supporting above the platen in a state of overlapping with the leading edge of the original.

According to a third aspect of the present invention, there is provided a document feeder which separates the originals supported by the supporting means for supporting the originals one by one, and a separating means which is provided above the platen, and which is forward from the separating means in the conveying direction. First guide means for guiding the fed original from a predetermined position on the platen to the platen, first detecting means for issuing an output signal when the original guided by the guide means is detected, and on the platen A transport unit that covers one end side of the platen from a predetermined position and reversibly transports the document guided by the guide unit to one end side or the other end side of the platen; and a transport unit that is juxtaposed to the transport unit on the platen. A platen provided directly below the separating means for covering a portion other than the portion covered by the conveying means and forming an entrance space for an original conveyed by the conveying means between the platen. A bar, a second guide means for guiding the document fed from one end of the platen by the transport means to the front in the transport direction, and a second guide for outputting an output signal when the document guided by the second guide means is detected. And the type of document size guided to the platen based on the output signal of the first detecting means,
It comprises a control means for stopping the conveying means and setting the document at a predetermined position based on the output signal of either one of the first and second detecting means.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention can be applied to a copying machine, various printers, facsimiles and the like. As an example, a document feeding apparatus applied to the copying machine will be described with reference to the accompanying drawings.

A copying machine M as an image forming apparatus shown in FIG.
A document feeder F is placed and mounted above the table. 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 an upper portion of the copying machine M, and the document feeder F placed so as to cover the platen P has a feeder 10 that covers a certain area corresponding to approximately half of the platen P. And a platen cover portion 20 that also covers the remaining area of the platen P, and a separate feed that is provided above the platen cover portion 20 and separates and feeds the original set on the original tray portion 30 toward the platen P. Unit 40, paper discharge unit 50 that receives the exposed document conveyed by conveyance unit 10 and discharges it from platen P, storage unit 60 that stores the document discharged by this paper discharge unit 50, and document conveyance device F 7 for supporting the upper part of the platen P of the copying machine M so as to be opened and closed.
0, and a drive / control unit 80. Figure 20
1 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. Is set 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 one-dot 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. FIG. 2 shows two drive motors M1 and M2 provided in the document feeder F, sensors S1 to S5 for collecting information necessary to control the operation of the document feeder F, and a control board 89. Has been done.

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 conveying 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 section 40 to the platen P, and detects the leading edge or the trailing edge of the original passing through the conveying path. 1 is a registration sensor as a detection unit.

The sensor S3 is a switchback sensor as a second detecting means for detecting the leading edge or the trailing edge of the original 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 so that the document transport device F can move the platen P with respect to the copying machine M.
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 is provided with a projecting member 62 extending in a direction substantially parallel to the document conveying direction. The projecting member 62 is for leaning a document stored in the storage section 60, and when the stored document is longer than the storage section 60, the tip thereof protrudes from the storage section 60, and the tip of the projecting document is protruded. Is to prevent the 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 arranged such that the image to be processed is placed on the lower side from the upstream side (the right side in FIG. 3) to the downstream side (the left side in FIG. 3) in the document feeding direction. A document tray unit 30 as a supporting unit or a first supporting unit for accumulating sheets, a separation feeding unit 40 as a separating unit that separates and conveys documents on the tray into one sheet, and a separation feeding unit 40. Received the originals transported by
Document transporting section 10 as a transporting means for transporting further downstream
Is provided.

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

In the document feeder F, the document tray section 30
Is composed of a loading tray 31 on which a document is placed, a pair of side edge guides 32L and 32R for regulating the side edges of the document set on the loading tray 31, and an auxiliary tray 33.

The side edge guides 32L and 32R are arranged in the width direction of the document along the guide guide 321 (vertical direction in FIG. 4).
Move to. 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.

In the separating / feeding unit 40, the platen P is moved from a predetermined position of the platen P (in this example, a point Y substantially at the center of the reading unit T) with the image to be processed on one original downside. A document conveying path R1 is formed as a first guiding means for guiding the document upward, and the document conveying path R1 is partitioned by guide plates 410 and 411. Then, along the document feeding path R1, there is arranged a separating means for separating the documents set on the tray 31 and feeding them one by one. That is, the pickup roller 42 is provided at the entrance side of the transport path R1 so as to be able to move forward and backward with respect to the mounting tray 31, and the paper feed roller 43 and the separation belt 44 enter the transport path R1 from the respective guide plates 410 and 411 so that they do not contact each other. They are arranged in a state of being overlapped with each other. Further, a registration roller 451 and a pinch roller 452 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 unit T defined on the upper surface of the platen P.

At the entrance of the conveying path R1, the presence or absence of a document on the loading tray 31 in cooperation with a document stopper 46 provided 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.

As shown in FIGS. 5 and 10, the document stopper 46, the pickup roller 42, the paper feed roller 43, and the separation belt 44 provided along the conveying path R1 are the motors M.
It is configured to rotate / rotate the power from No. 1 in a predetermined direction via belt drive transmission means 810, 811 and a plurality of gears G.

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 forward rotation of the motor M1 is performed 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 original stopper 46 and the lever are not transmitted. 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 reversely rotates, the lever 836
Is rotated to separate the pickup roller 42 from the surface of the original.

The document conveying section 10 as a conveying means includes an endless belt-like 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 presses for pressing the conveying belt 13 against the platen P. Laura 1
4 and. Further, the document transport unit 10 is provided with a read reference point X of the maximum copy document size (reading unit T) on the upper surface of the platen P.
It has a size enough to cover substantially half of the side (between X 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 the document transport unit 10, the document discharged from the exit of the transport path R1 is transported to the reference point X of the reading unit 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 exit of the document transport unit 10 (reference point X)
In the rear of the sheet, a document discharging section 50 is connected to the document conveying section 10.
Is provided. The paper discharge unit 50 includes 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 rotate in the forward and reverse directions, and a rolling roller 54 that transmits the drive of the conveyor belt 13 to the pulley 53. , Guide members 55 and 56 for guiding the document discharged from the exit of the document path R2 to the storage portion 60 as the second support and support, and the platen P by the conveyor belt 13 between the guide members 55 and 56.
Forming a discharge path R3 as a second guide means for guiding the document sent from one end of the document to the front in the transport direction.

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 transfer 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 54 are also provided.
As shown in the figure, they are in contact with each other at substantially the center of the conveyor belt 13.

The paper 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 accommodating portion 60 as the second supporting means is composed of an accommodating tray 61 and a projecting member 62 extending in a direction substantially parallel to the document conveying direction. 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.
It is placed and stored above the platen of. In other words, it is possible to configure a document conveying device that is small and lightweight, that is not particularly limited in the size of the document to be conveyed, and that can easily handle the processed document.

Referring to FIG. 3, FIG. 8 and FIG. 9, the platen cover section 20 comprises a separating and feeding section 4 as a separating means.
It is provided below (directly below) the platen P side of 0
And a support member 2 for supporting the platen cover 21 at a predetermined distance from the platen P and detachably supporting the document conveying apparatus F.
2, 23 and the platen cover 21 close to the platen P.
And an elevating means 24 for separating them.

The platen cover 21 has an engaging and fixing portion for engaging and fixing the platen cover 21 with respect 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 original 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 document feeding section 10, the drive system of the platen cover section 20 and the separation feeding section 4
A part of the drive system of 0 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. In addition, the rolling roller 54 provided above the driven pulley 12 of the conveyor belt 13 is
Drive is directly transmitted from the surface of the transport belt 13, and the paper discharge belt 51 is driven in the same 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 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 transmitted to the drive shaft 242 via the gears G11, G12, 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 connects the platen cover 21 to the conveyor belt 1.
Slide in the same direction as the transport direction in the reverse order of 3. 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. The platen cover 21 is held at the position indicated by the solid line in FIG. 8 with a constant force by the torque limiter 853 incorporated in the shaft 852.

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.

The hinge portion 70 shown in FIGS. 1, 4, 19 and 20 is composed of a hinge 71 with a spring for supporting the document feeder F on the upper surface of the copying machine M so that it can be opened and closed, and a hinge 72 without a spring. Has been done.

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, 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 (on the 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 (left and right 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 is composed of 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 13A to 13C 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 contacts the registration roller 451 and the pinch roller 452 in the stopped state after the leading edge of the document D 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 Function) The document D conveyed through the conveyance path R1 as described above is guided 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 driven in synchronization with the registration rollers 451.
The document path R2 is sent forward by.

At this time, the length of the document D in the transport 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 transported 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) As shown in FIG. 17, when the original has a small size, the pulse generating means 8 is started after the rotation of the motor M2 is started.
After 7 counts a predetermined pulse (A pulse), the conveyor belt 13 is stopped. 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 if the presence of the original D is not detected, the copying machine M is operated to execute copying.

When copying is completed, the transport 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 first (first) document is stored in the storage tray 6 with the rear end thereof being restrained by the paper discharge unit 50.
No. 1 is discharged on the tip side. (See FIG. 13B) When the empty sensor S1 detects the document D to be copied on the mounting tray 31, the above-described operation is appropriately repeated,
As shown in FIG. 13C, the copied documents D are sequentially accumulated in the storage tray 61.

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

The conveyance of the above-mentioned original is started (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 a large size. To do. In this case, the conveyance of the document D 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 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 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 is printed on the platen P between the points Y and Z of the reading unit T and the platen cover 2
Enter between 1 and.

The original D is fed backward by the conveyor belt 13 until the leading edge of the original 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 1 is provided until the pulse generating means 87 counts a predetermined pulse (B pulse) after the trailing edge of the document (the trailing edge during forward feeding; the right side in the figure) passes the registration sensor S2.
In consideration of the size of the used document, the switchback sensor S3 is provided near the downstream side of the platen P in the forward feeding direction so that the leading edge of the document is always detected by the switchback sensor S3 when the document 3 is conveyed. It is arranged.

It should be noted that 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 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 by the conveying belt 13 in the forward direction, and the trailing end of the document D fed in the forward direction is 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, when the document D is conveyed by D pulses by the forward rotation of the conveyance belt 13, the platen cover 21 moves in the direction in which the platen cover 21 approaches the platen P. As a result, the point Y-Z of the reading unit T
The document D that has entered between the platen P and the platen cover 21 in between is pressed to the platen P side. Then, copy is executed.

After the copying is completed, if the empty sensor S1 does not detect the original on the tray 31, the conveyor belt 13 and the discharge belt 51 are driven in the forward feeding direction to store the original D through the 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 discharge belt 51 at the same time.
As a result, the copied document D1 is sent to the storage tray 61, and the subsequent document D2 is transferred to the point Y of the reading unit T.
The document D is advanced by the conveyor belt 13 until the trailing edge of the document is located at the point Y of the reading unit T, as described above. (FIG. 15 (D)) According to the document feeder F having the above-described configuration, a relatively small size document feeder system having a relatively small size of about half (X-Y size) of the reading unit T on the platen P or less is large. Manuscript (X
It is possible to effectively carry out the transfer process even in the (Z-to-Z size), so that the system can be rationalized, the cost of the device can be reduced, and the size and weight can be reduced.

In the above embodiment, about twice the small size is set as the large size, but it goes without saying that 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.

[0081]

According to the document feeding apparatus of the first aspect, the separating means is arranged directly above the platen cover.
The relatively small size of the document feeder, which is less than half the size on the platen, makes it possible to effectively carry and read even large documents, while streamlining the carrying system and reducing the size and weight of the device. Can be achieved.

According to the document feeder of the second aspect,
Since the leading end of the original document on the first supporting means and the original document on the second supporting means are supported above the platen in a state of being overlapped with each other, it is possible to use a small original feeding device of a relatively small size of about half or less on the platen. In addition, it is possible to effectively carry out the carrying / reading process even for a large-sized document, and it is possible to achieve rationalization of the carrying system and reduction in size and weight of the apparatus.

According to the document feeder of claim 3,
Depending on the size of the document to be conveyed, the detection means arranged on the upstream side and the downstream side of the document in the guide direction are selectively used to control the stoppage of the conveyance means. Therefore, the original is determined with a reasonable conveyance amount adapted to each size. Can be efficiently and accurately transported to the position.

[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 document feeder as above.

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

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

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 flow chart for explaining the separating / conveying operation of the document conveying device.

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

FIG. 18 is a flow chart illustrating a conveyance / paper discharge operation of 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.

[Explanation of symbols]

M Copier (image forming device) F Document feeder P Platen D manuscript 10 Document transport section (transport means) 20 Platen cover part 30 Document tray section (supporting means, first supporting means) 40 Separation Feeding Unit (Separation Means) 50 paper output section 60 Storage (second support means) 70 Hinge part S2 registration sensor (first detection means) S3 switchback sensor (second detection means) R1 transport path (first guide means) R3 paper discharge path (second guide means)

Claims (3)

[Claims] 1. A document feeder of an image forming apparatus having a substantially horizontal platen, which is provided above the platen for separating (a) the documents supported by a supporting means for supporting the documents one by one. Separating means; (b) guiding means for guiding a document sent forward from the separating means in the transport direction from a predetermined position on the platen to the platen; and (c) one end of the platen from a predetermined position on the platen. Transporting means for reversibly transporting the document guided by the guiding means to one end side or the other end side of the platen, and (d) the transport means arranged on the platen in parallel with the transport means. While covering the part other than the one covered by the transport means,
An original feeding device for an image forming apparatus, comprising: a platen cover which is provided directly below the separating means and which forms an entrance space for an original conveyed by the conveying means between the platen and the platen. 2. A document feeder for an image forming apparatus having a substantially horizontal platen, wherein (a) the document is placed substantially horizontally, and at least the leading end of the placed document is supported above the platen. First to do
And (b) a separating means provided above the platen for separating the documents supported by the supporting means one by one, and (c) a document sent forward from the separating means in the transport direction. First guide means for guiding the platen from a predetermined position on the platen to the platen, and (d) one end of the platen is covered from the predetermined position on the platen, and the document guided by the guide means is moved to the platen Conveying means for reversibly conveying to one end side or the other end side, (e) while being arranged in parallel with the conveying means on the platen and covering a portion of the platen other than covered by the conveying means,
A platen cover provided directly below the separating means for forming an entrance space for an original conveyed by the conveying means between the platen, and (f) a platen cover connected to one end side of the conveying means, Second guide means for guiding the fed original to the upper side of the platen while reversing the original; and (g) second guide means provided near the upper side of the separating means, the first guide means and the conveying means. Second supporting means for supporting the original guided by the platen above the platen in a substantially horizontal state and overlapping with the leading end of the original supported by the first supporting means. A document feeding device for an image forming apparatus, which is characterized by: 3. A document feeder of an image forming apparatus having a substantially horizontal platen, which is provided above the platen for separating (a) the documents supported by the supporting means for supporting the documents one by one. Separating means; (b) first guiding means for guiding the document sent forward from the separating means in the conveying direction from a predetermined position on the platen to the platen; and (c) document guided by the guiding means. And (d) one side of the platen which covers one end side of the platen from a predetermined position on the platen and which is guided by the guiding means. And a conveying means for reversibly conveying to the side, and (e) covering a part of the platen other than the platen arranged in parallel with the conveying means and covered by the conveying means,
A platen cover provided directly below the separating means for forming an entrance space for an original conveyed by the conveying means between the platen; and (f) a document sent from one end of the platen by the conveying means. Second guiding means for guiding forward in the conveying direction; (g) second detecting means for outputting an output signal when a document guided by the second guiding means is detected; and (h) facing the platen. After determining the type of document size to be guided based on the output signal of the first detecting means, the conveying means is stopped based on the output signal of one of the first and second detecting means. A document feeding device for an image forming apparatus, comprising: a control unit that sets a document at a predetermined position by a means.