JPH09165144A - Automatic document conveying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To discharge a document smoothly even in the case of no document existing on a document table by driving a feed motor to operate a feed belt of a vacuum separative feeding means when a document detecting sensor outputs a signal indicating no document on the document table at the time of discharging a first document. SOLUTION: A document set on a document table 12 is conveyed onto a transparent plate 8 so as to be subjected to exposure treatment and then returned onto the document table 12 by a document discharge means. At this time, in the case of a third document detecting sensor being turned off, it is so judged that no document exists on the document table 12, and a control means drives an electric motor 60 (M1) and energizes an electromagnetic clutch 35 (CLT1). A feed belt 32 of a vacuum separative feeding means 24 is therefore operated. Accordingly, even if the front end of the discharged document comes in contact with the feed belt 32, the front end of the document is not caught since the feed belt 32 is moving in a document conveying direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic document feeder installed in a document processor such as an electrostatic copying machine, and more particularly to an automatic document feeder equipped with a vacuum type document separating / feeding means.

[0002]

2. Description of the Related Art In recent years, a copying machine has come to use an automatic document feeder for automatically feeding a plurality of documents to a document setting position on the upper surface of a transparent plate in accordance with the speeding up and automation of the copying process. There is. This kind of automatic document feeder has
A document separating / feeding mechanism is provided for separating and feeding the lowest one of a plurality of documents placed on a document table. This type of document separating / feeding mechanism includes a plurality of documents which are arranged below a guide plate arranged in front of the document table in the conveying direction and which are projected upward through an opening formed in the guide plate. What is generally used is composed of a feeding roller having a roller and a separating belt mechanism which is arranged above the feeding roller so as to face the feeding roller. However, since such a document separating / feeding mechanism is configured such that a large frictional force acts between the lowest document and the second document from the bottom, the lowest document is In the case of writing with a writing instrument such as a pencil, which tends to fall off by frictional contact, there is a problem that the back surface of the second document from the bottom is stained by the lowest document.

As a document separating / feeding mechanism for solving the above problems, a document table having an opening at the front portion in the document conveying direction,
A vacuum chamber disposed below the opening of the document table and having an opening on the upper surface, a driving roller and a driven roller disposed parallel to each other on the front side and the rear side of the vacuum chamber in the document transport direction, and the driving roller. A lowermost original among the originals placed on the original table, including a driven roller and a vacuum separating / feeding means provided with a feeding belt having a plurality of holes wound around the vacuum chamber. The document separating and feeding mechanism of the automatic document feeder is designed to feed while adsorbing the
For example, JP-A-56-56443 and JP-A-62.
No. 93141.

On the other hand, the original fed by the original separating / feeding mechanism is conveyed onto a transparent plate, exposed on the transparent plate, returned to the original set on the original table, and repeatedly processed. A so-called circulation type automatic document feeder which is made possible has also been put into practical use.

[0005]

When the number of originals set on the original table is small, the first original is fed by the original separating / feeding mechanism and subjected to exposure processing, and then placed on the original table. If none of the originals are set on the original table when ejected, the front edge may be caught by the rubber feeding belt that constitutes the vacuum type original separating and feeding mechanism, causing the original to be broken or jammed. Become.

The present invention has been made in view of the above facts, and its main technical problem is that when the first document set on the document table is fed, exposed, and then discharged, An object of the present invention is to provide an automatic document feeder that can smoothly eject a document even when there is no document on the document table.

[0007]

According to the present invention, in order to achieve the above-mentioned technical objects, a document table having an opening at a front portion in the document conveying direction, and an upper surface below the opening of the document table. Is provided with a vacuum chamber which is arranged substantially flush with the upper surface of the original table and has an opening in the upper surface, and a plurality of holes which are arranged by winding the vacuum chamber and are operated in the original conveying direction. A vacuum separating and feeding means including a belt and a separating air ejecting means for ejecting air toward a front end of a document placed on the document table;
Of the vacuum separating and feeding means, the original document conveying means for conveying the original document fed on the transparent plate onto the transparent plate, the original document ejecting means for ejecting the original document on the transparent plate onto the original document table, and the vacuum separating and feeding means. A feeding motor that drives a feeding belt, a feeding motor that drives the document feeding unit, a discharge motor that drives the document discharging unit, a document detection sensor that detects the presence or absence of a document on the document table, A control unit for driving and controlling the feeding motor, the conveyance motor and the discharge motor based on a detection signal from the document detection sensor, wherein the control unit discharges the first document by the document discharge unit. At this time, when the document detecting sensor outputs a signal indicating that there is no document, the automatic document feeder is characterized in that the feeding motor is driven to operate the feeding belt of the vacuum separating and feeding means. There is provided.

Further, according to the present invention, the control means drives and controls the feeding motor so that the moving speed of the feeding belt becomes substantially the same as the document discharging speed by the document discharging means. Will be provided.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a document separating and feeding mechanism of an automatic document feeder according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows an upper end portion of an electrostatic copying machine 2 and an automatic document feeder 4 mounted on the upper end portion. The electrostatic copying machine 2 has a housing 6, and a transparent plate 8 which may be a glass plate is arranged on the upper surface of the housing 6. On one side (the left side in FIG. 1) of the transparent plate 8, a document regulating member 10 that determines a document setting reference position is arranged.
An automatic document feeder 4 having a document separating / feeding mechanism constructed according to the present invention has a turning axis extending along a rear side edge of a transparent plate 8 on the upper surface of a housing 6 of an electrostatic copying machine 2. It is mounted so that it can rotate freely. When a document is manually placed on the transparent plate 8 of the electrostatic copying machine 2, the automatic document feeder 4 is swung upward from the closed position shown in the drawing to the open position to expose the transparent plate 8. A document is placed at a desired position on the transparent plate 8, and the automatic document feeder 4 is set to the closed position shown to cover the transparent plate 8 and the document placed on the transparent plate 8. When a document is placed on the transparent plate 8, one edge of the document is brought into contact with the leading edge of the document regulating member 10 and the one edge of the document is positioned at the document setting reference position so that the document is placed at a desired position. Can be positioned at. A document is automatically loaded onto the transparent plate 8 using the automatic document feeder 4,
When the document is automatically carried out from the transparent plate 8, the automatic document feeder 4 is used in the closed position.

Continuing the description with reference to FIGS. 1 and 2, the illustrated automatic document feeder 4 is provided with a document table 12 as document placing means. The manuscript table 1
2 includes a large first portion at the front side (the left side in FIGS. 1 and 2) in the document conveyance direction on the back side (the upper side in FIG. 2).
Of the first opening 1
A second opening 16 smaller than the first opening 14 is formed at the front side (the left side in FIG. 2) in the document conveying direction on the front side of 4. In addition, the second
A pair of guide grooves 18, 18 extending in the width direction is provided on the rear side of the opening 16 in the document conveying direction. Support leg portions of a width regulating member 20 for regulating the widthwise position of a document placed on the document table 12 are fitted into the pair of guide grooves 18, 18, and the width regulating member 20 is provided as a pair of guide grooves. 18, 18
It is configured to be movable in the up and down direction in FIG. In the automatic document feeder 4 in the illustrated embodiment, the position reference of the document placed on the document table 12 is the back side (one side) reference.
The widthwise position of the document placed on the document table 12 is regulated by the inner surface of the side plate 22 and the inner surface of the width regulating member 20 which are formed upright on the back side of the document 2. A sensor hole 17 is provided on the rear side of the front end of the document table 12 in the document transport direction, and a reflection-type first document detection including a light emitting element and a light receiving element is provided below the sensor hole 17. The sensor 21 (SW1) is provided. The first document detection sensor 21 (SW1) detects a document placed on the document table 12 and sends a detection signal to the control means 100 described later. Further, the document table 12 is provided with a sensor hole 18 at a position corresponding to a front side (lower side in FIG. 2) of the second opening 16, and a light emitting element and a light receiving element are provided below the sensor hole 18. The second reflection-type original document detection sensor 23 (SW2) is provided. This second document detection sensor 23 (SW
In 2), when the size of the original placed on the original table 12 in the width direction is larger than the second opening 16 from the inner surface of the side plate 22, that is, when the original placed on the original table 12 is the second original.
It functions as a document detecting means for detecting whether or not it is located on the opening 16 and sends the detection signal to the control means described later. The document detecting means for detecting whether or not the document placed on the document table 12 is positioned on the second opening 16 is a device for detecting the document size by the moving position of the width regulating member 20. The detection signal may be used.
Further, the document table 12 is provided with a sensor hole 25 at the rear side of the first opening 14 in the document transport direction, and below the sensor hole 25, there is provided a third reflective type light emitting element and a light receiving element. A document detection sensor 27 (SW3) is provided. The third document detection sensor 27 (SW3) detects whether or not a document exists on the first opening 14 of the document table 12, and sends a detection signal to the control means 100 described later.

A vacuum separating / feeding means 24 is provided below the original table 12 in correspondence with the first opening 14. This vacuum separating and feeding means 24 is
Vacuum chamber 26 and the vacuum chamber 26
Of the driving roller 28 and the driven roller 30, which are arranged in parallel to each other on the front side and the rear side of the original conveying direction, the driving roller 28, the driven roller 30, and the vacuum chamber 26.
Is provided and is provided with four feeding belts 32. The vacuum chamber 26 is made of a synthetic resin, and has four openings 261 on the front side in the original conveying direction and four openings 262 on the rear side in the original conveying direction of the four openings 261 on the upper wall. ing. The vacuum chamber 26 thus configured is attached to the lower surface of the original table 12 by an appropriate supporting means (not shown) so that the upper surface thereof is substantially flush with the upper surface of the original table 12. The vacuum chamber 26 is connected to a suction blower 36 via a duct 34 connected to a hole (not shown) formed in a wall on the back side thereof. The drive roller 28 is provided so as to penetrate through support walls 263 and 264 provided so as to project from both side walls of the vacuum chamber 26 to the front side in the document transport direction, and one end of the drive roller 28 is downward from the lower surface on the back side of the document table 12. A rotary shaft 281 rotatably supported by a bearing 38 on a support wall 122 provided so as to project, and the four openings 261 in the rotary shaft 281 and four rotary shafts 281 corresponding to the document transport direction. The roller 282
It consists of Drive roller 2 configured in this way
8, the other end of the rotary shaft 281 is an electromagnetic clutch 35 (CLT
It is connected to the output side of 1). Electromagnetic clutch 35 (C
The input side of LT1) is rotatably supported on the support wall 121 by a bearing 37 and is connected to a drive shaft 390 having a roller drive gear 39 mounted thereon. The electromagnetic clutch 35
(CLT1) is biased by the control means 100 described later. The roller drive gear 39 mounted on the drive shaft 390 is transmitted to an electric motor 60 (M1) as a paper feed motor through power transmission mechanisms 601, 602 and 603 such as a gear mechanism and a belt mechanism as shown in FIG. It is connected. The electric motor 60 (M1) is provided with a rotation amount detecting means 600 (FG) such as a rotary encoder or a frequency generator which constitutes the document conveying amount detecting means.
1) is attached, and a pulse signal as a detection signal thereof is sent to the control means 100 described later. The driven roller 30 is provided with support walls 265 and 26 provided so as to project from the both side walls of the vacuum chamber 26 to the rear side in the document conveying direction.
6, a shaft 301 supported by the shaft 6, and the four openings 262 in the shaft 301 and four rollers 302 rotatably arranged in correspondence with the document conveying direction. The four feeding belts 32 have a plurality of holes 321 and
The drive roller 28 and the driven roller 30 are respectively wound around the rollers 282 and the rollers 302 corresponding to the document conveying direction. The feeding belt 32 configured in this way
Is arranged so that its upper surface is slightly above the upper surface of the document table 12.

Below the original table 12, as shown in FIG. 2, the feeding drum 4 is provided corresponding to the second opening 16.
0 is provided. As shown in FIGS. 3 and 4, the feeding drum 40 is made of synthetic resin and is provided with a plurality of holes 401 around it. One end of the feeding drum 40 is open, and the duct 42 connected to the vacuum chamber 26 is inserted from the opened one end. The duct 42 includes a suction section 421 and a connection section 422. The suction part 421 has an opening 4 as shown in FIG.
Equipped with 23. The opening 423 is formed such that only the upper side of the suction portion 421 is opened in the axial direction. The upper end sides of the side walls 424 and 425 of the duct 42 forming the opening 423 are configured to be as close as possible to the inner peripheral surface of the feeding drum 40. Therefore, each of the plurality of holes 401 formed in the feeding drum 40 faces the opening 423 of the duct 42 and communicates with the duct 42 only when positioned above. Connection part 42 constituting the duct 42
A bearing 44 is provided between one end of the second suction unit 421 side and one end of the feeding drum 40, and the feeding drum 40 is rotatably supported by the duct 42. Between the duct 42 and the vacuum chamber 26, an opening / closing valve 46 that constitutes an opening / closing means that connects or disconnects the vacuum chamber 26 and the feeding drum 40 is provided. The open / close valve 46 includes a valve housing 461 and a butterfly valve 463 mounted on a valve shaft 462 mounted on the valve housing 461.
One end of the valve housing 461 is inserted and connected into the vacuum chamber 26 through a connection hole 267 formed in the side wall of the vacuum chamber 26. A flange 464 is provided on the outer circumference of one end of the valve housing 461, and the insertion into the vacuum chamber 26 is restricted. The flange 464 is fixed to the side wall of the vacuum chamber 26 by a fixing means such as a screw. The other end of the valve housing 461 has the duct 4
The second duct 42 is inserted and connected to the other end of the connecting portion 422. A flange 465 is also provided on the outer periphery of the other end of the valve housing 461, and the duct 42
Insertion inside is restricted. The on-off valve 46 configured as described above has the valve shaft 462 on which the lever 4 is attached.
66 is mounted, and the lever 466 is connected to a plunger of a solenoid 468 (SOL1) (see FIG. 1) via a link mechanism. Solenoid 468 (SOL
Butterfly valve 463 operated by 1)
Is in a closed state when the solenoid 468 (SOL1) is deenergized, and opens when the solenoid 468 (SOL1) is energized. The solenoid 468 (SOL1) is used for the second document detection sensor 23.
When (SW2) does not detect the document, it is deenergized,
When the second document detection sensor 23 (SW2) detects the detection of a document, it is energized by the control means 100 described later.

An end wall 402 is provided at the other end of the feeding drum 40.
Is provided. At the center of this end wall 402 is a boss 4.
03 is formed, and the shaft fitting hole 404 is formed in the boss 403.
And a pin fitting groove 405 are provided. Feeding drum 40
One end portion of the rotary shaft 48 is fitted into the shaft fitting hole 404 provided in the boss 403 of the end wall 402 constituting the. The rotation shaft 48 has a pin insertion hole 4 that passes through the axis and penetrates in the radial direction.
81 is formed, and the pin 50 fitted in the pin insertion hole 481 has the pin fitting groove 4 formed in the boss 403.
05, the driving force of the rotary shaft 48 is transmitted to the feeding drum 40. Rotary axis 4
8 between the one end inserted into the feeding drum 40 and the one end of the suction portion 421 forming the duct 42.
2 is disposed, and the other end of the duct 42 is supported by one end of the rotating shaft 48 so as to be relatively rotatable. This rotating shaft 48
Has an intermediate portion rotatably supported by a support wall 123 provided so as to project downward from the lower surface of the original table 12 via a bearing 54, and the other end thereof is supported by the electromagnetic clutch 5.
6 (CLT2) is connected to the output side. The input side of the electromagnetic clutch 56 (CLT2) is rotatably supported on the support wall 121 by a bearing 58 and connected to a drive shaft 590 having a feed drum drive gear 59 mounted thereon. Drive shaft 590
The feed drum drive gear 59 mounted on the roller drive gear 39 is transmission-coupled to the roller drive gear 39 via an intermediate gear 62 as shown in FIG. The number of teeth of the intermediate gear 62 as a driving means for transmitting power from the roller driving gear 39 to the driving shaft 590 of the feeding drum 40 and the number of teeth of the feeding drum driving gear 59 are the driving rollers of the vacuum separating feeding means 24. 28
The moving speed of the feeding belt 32 and the peripheral speed of the feeding drum 40, which are operated by, are set to be substantially the same. The electromagnetic clutch 56 (CLT2)
Is deenergized when the second original detection sensor 23 (SW2) does not detect the original, and when the second original detection sensor 23 (SW2) detects the original, it is controlled by the control means 100 described later. It is supposed to be urged.

The vacuum separating / feeding means 24 has a separating air ejecting means 63, which is a so-called air knife, arranged above the front end of the original table 20 in the original conveying direction. The separation air ejecting means 63 is composed of an air chamber 631 connected to a blower (not shown) and a nozzle 632 for ejecting the air in the air chamber 631 toward the front end of the document placed on the document table 20. There is. When the air is ejected from the nozzle 632 of the separation air ejecting means 63 configured as described above, the air is blown between the respective originals placed on the original table 20 to perform a so-called separation action for separating the respective originals. Be seen.

A set original document stopper 64 and a discharged original document stopper 66 are disposed above the front end of the vacuum separating and feeding means 24 in the original document conveying direction. The set document stopper 64 is configured so that its lower end is located at a set position where it comes into contact with the upper surface of the document table 12 and an operating position which is located a few mm above the upper surface of the document table 12. The discharged document stopper 66 is the set document stopper 6
Operation piece 661 disposed on the rear side in the original conveyance direction of No. 4 and placed on the original set on the original table 12 by its own weight.
It has. The action piece 661 is configured to descend by its own weight as a document set on the document table 12 is fed, and the movement of the discharged document fed from the document table 12 and discharged as described later. Function to regulate. The ejected document stopper 66 is configured to retract upward from the illustrated operating position when the document is set.

Continuing the description with reference to FIG. 1, a pair of paper feed rollers 70 is provided downstream of the original table 20 in the original conveying direction.
Are arranged. The paper feed roller pair 70 is composed of a drive roller 701 and a driven roller 702. The drive roller 701 is power-transmitted and connected to the electric motor 60 (M1) via power transmission mechanisms 601 and 602, and is indicated by an arrow. It is driven to rotate. On the downstream side of the paper feed roller pair 70, an original carry-in path 72 for guiding the original fed by the paper feed roller pair 70 onto the transparent plate 8 is provided. A pair of registration rollers 74 is arranged in the original carry-in path 72. The registration roller pair 74 is composed of a driving roller 741 and a driven roller 742. The driving roller 741 is transmission-coupled to the electric motor 60 (M1) via a power transmission mechanism 601 and an electromagnetic clutch 75 (CLT3). There is. In addition, a reflection type incoming original detection sensor 720 (SW4) including a light emitting element and a light receiving element is provided on the upstream side of the registration roller pair 74 in the original loading path 72.
Are arranged. The incoming document detection sensor 720 (SW
In 4), the document passing through the document carry-in path 72 is detected, and the detection signal is sent to the control means 100 described later.

A conveyor belt mechanism 7 is provided above the transparent plate 8.
6 are provided. The transport belt mechanism 76, which constitutes the document transport means, includes a drive roller 761 and a driven roller 762, which are arranged at intervals in the transport direction of the transparent plate 8, and an endless belt wound around the drive roller 761 and the driven roller 762. Belt 763, driving roller 761 and driven roller 7
62 and rolling rollers 764a, 764
b, 764c, 764d, 764e. The lower running portion of the endless belt 763 extends along the transparent plate 8 of the electrostatic copying machine 2, and a document transport path 78 is defined between the two. In the transport belt mechanism 76 configured as described above, the drive roller 761 as a transport motor is power-connected to the electric motor 61 (M2) via the power transmission mechanism 611. The electric motor 61 (M2) is equipped with a rotation encoder 610 (FG2) such as a rotary encoder or a frequency generator that constitutes a document conveyance amount detector, and a pulse signal as a detection signal thereof will be described later. To the control means 100.

On the right side of the document transport path 78 in FIG. 1, a document unloading path 80 which constitutes a document discharging means is provided. In the document carry-out path 80, conveying roller pairs 82 and 84 and a discharge roller pair 86 are arranged. The transport roller pairs 82 and 84 are drive rollers 821 and 84, respectively.
1 and driven rollers 822 and 842, and the discharge roller pair 86 also includes a drive roller 861 and a driven roller 862. These drive rollers 821, 841, and 861 are electric motors 62 (M
3) is transmission-coupled to the motor 3) via power transmission mechanisms 621, 622, and 623, and is rotationally driven in the directions indicated by arrows. The electric motor 62 (M3) is equipped with a rotation encoder 620 (FG3) such as a rotary encoder or a frequency generator that constitutes a document conveyance amount detector, and a pulse signal which is a detection signal thereof will be described later. It is sent to the control means 100. A reflection type discharged original detection sensor 800 (SW5) including a light emitting element and a light receiving element is arranged on the upstream side of the discharge roller pair 86 in the original discharge path 80. The output document detection sensor 800 (SW5) is
A document passing through the document carry-out path 80 is detected, and the detection signal is sent to the control means 100 described later. Below the discharge roller pair 86, an extruding plate 88 is arranged which is movable in the left-right direction in FIG. 1 by a predetermined amount. The pushing plate 88 supports the rear end of the document discharged by the discharge roller pair 86 and stopped by the discharge document stopper 66, and pushes the discharged document leftward in FIG. 1 to set the document stopper 64. It has the function of moving up to. Therefore, the moving amount of the pushing plate 88 is set to the distance between the set original document stopper 64 and the discharged original document stopper 66. The discharge roller pair 86 and the pushing plate 88 constitute a discharge unit,
According to the size of the document placed on the document table 20, it is movable in the left-right direction in FIG. For the moving mechanism of the discharging unit constituted by the discharging roller pair 86 and the pushing plate 88, the moving mechanism of the pushing plate 88, and the like, for example, the technique disclosed in Japanese Patent Laid-Open No. 3-95077 can be used. Since the moving mechanism of the discharging unit and the moving mechanism of the pushing plate 88 are not directly related to the present invention, detailed description thereof will be omitted.

Next, the control means 100 will be described with reference to FIG. The control means 100 is composed of a microcomputer, and a central processing unit (CPU) 101 that performs arithmetic processing according to a control program and a read-on memory (ROM) 102 that stores the control program.
And a readable / writable random access memory (RAM) 103 for storing calculation results and the like, a timer 104, a counter 105, an input interface 106 and an output interface 107. The input interface 106 of the control means 100 thus configured
Includes the first document detection sensor 21 (SW1) and the second document detection sensor 21 (SW1).
Document detection sensor 23 (SW2), third document detection sensor 27 (SW3), carry-in document detection sensor 720 (SW
4), discharged original detection sensor 800 (SW5), rotation amount detection means 600 (FG1), 610 (FG2), 620
(FG3) or the like is inputted with a detection signal, and the output interface 107 outputs the electric motors 60 (M1), 61.
(M2), 62 (M3), electromagnetic clutch 35 (CLT
1), 56 (CLT2), 75 (CLT3), solenoid 468 (SOL1), etc., and outputs a control signal. Also,
The control means 100 is connected to the control means 200 of the electrostatic copying machine 2, and control signals are exchanged between them. An operation unit 201 and a display unit 202 are connected to the control unit 200 of the electrostatic copying machine 2. As shown in FIG. 1, the operation means 201 is arranged on the upper surface of the front portion of the electrostatic copying machine 2, and is provided with copy operation operation keys such as a copy start key, a copy number designation key, a double-sided copy designation key, and a copy action stop key. The copying information is input to the control means 200 of the electrostatic copying machine 2. The display means 202 is the operation means 201.
Similarly to the above, the electrostatic copying machine 2 is arranged on the upper surface of the front side of the electrostatic copying machine 2 adjacent to the operation means 201 and displays copy information, failure information and the like.

The automatic document feeder according to the illustrated embodiment is configured as described above, and its operation will be described below. First, the case of using a document having a small width dimension such as A4 or B5 size will be described. Set document stopper 64 with the front edge at the set position for the document to be copied
The width regulating member 2 is contacted and placed on the document table 12.
2 is moved upward in FIG. 2 to regulate the position of the document in the width direction by the inner surface of the side plate 22 and the inner surface of the width regulating member 20. When an original having a small width is set on the original table 12 as described above, the position of the front edge of the original, that is, the lower edge in FIG.
6 has not been reached. In this way, the original table 12
When a document is set on the first document detection sensor 21
(SW1) detects that a document is set on the document table 12, and the detection signal is sent to the control means 100. When the copy start key of the operation means 201 is pressed in this state, a copy start signal is sent from the control means 200 of the electrostatic copying machine 2 to the control means 100, and the control means 100 is automatically operated based on this copy start signal. The components of the document feeder are operated and controlled. First, the pushing plate 88 is moved from the position indicated by the solid line to the position indicated by the chain double-dashed line by a moving mechanism (not shown), the copying operation is started, the suction blower 36 is driven, and the air in the vacuum chamber 26 is sucked. To be done. On the other hand, since the air is jetted from the nozzle 632 of the separation air jetting means 63 toward the front end of the document placed on the document table 20, the air is blown into each document placed on the document table 20, Each document is separated and the lowest document is separated and attracted to the feeding belt 32. When the copy start signal is sent to the control means 100, the set original document stopper 64 is positioned at an operating position located a few mm above the upper surface of the original document table 12, and the discharged original document stopper 66 is set on the original document table 12. It is operated so as to come into contact with the document that has been printed. On the other hand, when the copy start signal is sent to the control means 100, the control means 100 turns on the electric motor 60 (M1).
At the same time, the electromagnetic clutch 35 (CLT1) is urged to rotate the drive roller 28 in the direction indicated by the arrow. When the drive roller 28 rotates, the feeding belt 32 is actuated in the direction indicated by the arrow, and thus the lowest document adsorbed on the feeding belt 32 as described above is fed to the downstream side in the conveying direction. . When using a document having a small width, the second document detection sensor 23 (SW
2) does not detect the document, the solenoid 468 is
Since (SOL1) is deenergized, the opening / closing valve 46 is closed and the vacuum chamber 26 and the feeding drum 4 are closed.
Communication with 0 is blocked. If the second document detection sensor 23 (SW2) does not detect the document, the electromagnetic clutch 56 (CLT2) is also deenergized,
The feeding drum 40 is also stopped.

The original fed by the vacuum separating / feeding means 24 as described above is conveyed to the original feeding path 72 by the pair of paper feeding rollers 70, and the front end of the original is detected by the incoming original detecting sensor 720 (SW4). After a lapse of a predetermined time from when the electric motor 60 (M1) is turned off, the electromagnetic clutch 75 (CLT3) is deenergized and brought into contact with the nip portion of the registration roller pair 74 which is in the inoperative state. Then, the primary paper feeding is completed. Next, when the electric motor 60 (M1) is turned on again and the electromagnetic clutch 75 (CLT3) is energized to activate the registration roller pair 74, the original document fed to the nip portion is the electrostatic copying machine 2 The document is conveyed toward a document conveying path 78 extending along the transparent plate 8. Further, the electric motor 61 (M2) is driven, and the conveyor belt mechanism 76, which constitutes a conveyor means, conveys the transparent plate 8 from the left side to the right side in FIG. 2, and is positioned at a predetermined position. The paper is finished. The exposure operation is executed in this state.

When the exposure operation of the original document positioned on the transparent plate 8 is completed as described above, the electric motor 61 (M2) is driven again and the electric motor 62 is driven.
(M3) is driven. Therefore, the conveyance belt mechanism 76 is operated to convey the original document on the transparent plate 8 toward the original document discharge path 80, and the original document conveyed to the original document discharge path 80 is discharged by the conveying roller pairs 82 and 84. The discharge roller pair 86 is conveyed toward the pair 86.
From the original document table 12 is carried onto a set original document placed on the original document table 12. At this time, the front end of the discharged original is brought into contact with the discharged original stopper 66 to be distinguished from the original set first. Further, the rear end portion of the document discharged onto the document table 12 is supported on the push-out plate 88 positioned at the position indicated by the chain double-dashed line in FIG. In this way, when all the set originals placed on the original table 12 are fed and returned to the original table 12 after the exposure operation, the discharged original stopper 66 is retracted upward from the illustrated operating position. And set document stopper 6
4 is operated from the illustrated operating position to a setting position in which the lower end thereof contacts the upper surface of the original table 12. On the other hand, the pushing plate 88 is moved from the position shown by the chain double-dashed line in FIG. 1 to the position shown by the solid line by a moving mechanism (not shown).
By moving the pushing plate 88 to the position shown by the solid line,
The trailing edge of the document discharged onto the document table 12 and supported on the pushing plate 88 is dropped onto the document table 12. When the original discharged on the original table 12 is to be copied again, the pushing plate 88 is moved to the position shown by the chain double-dashed line in FIG. 1 by the moving mechanism (not shown), and is returned to the original table 12. The original is pushed to the left in the figure by the push-out plate 88, and its front end is brought into contact with the set original stopper 64 to be set again.

Next, the case of using a document having a large widthwise dimension such as A3 or B4 size will be described. The width regulating member 20 is moved to the front side of the second opening 16, that is, downward in FIG.
It is placed on the upper side, and the width regulating member 20 is moved to the upper side in FIG. In this way, when an original having a large widthwise dimension is set on the original table 12 as described above, the original is placed in the first opening 14 and the second opening.
It is mounted over the opening 16 of the. In this way,
When a document is set on the document table 12, the first document detection sensor 21 (SW1) and the second document detection sensor 23 (SW2) detect that the document is set on the document table 12, The detection signal is sent to the control means 100.
Send to When the copy start key of the operation means 201 is pressed in this state, a copy start signal is sent from the control means 200 of the electrostatic copying machine 2 to the control means 100, and the control means 100 is automatically operated based on this copy start signal. The above-mentioned components of the document feeder are operated and controlled as described above. The copying operation is started, the suction blower 36 is driven, and the air in the vacuum chamber 26 is sucked. In addition, as described above, the second
When the original detection sensor 23 (SW2) detects the original,
The control means 100 energizes the solenoid 468 (SOL1) and opens the open / close valve 46 to open the vacuum chamber 2
6 and the feeding drum 40 can communicate with each other. On the other hand, since the air is jetted from the nozzle 632 of the separation air jetting means 63 toward the front end of the document placed on the document table 20, the air is blown into each document placed on the document table 20, The originals are separated, the lowest original is separated and adsorbed to the feeding belt 32, and the feeding drum 40
Can also be adsorbed on. Further, when the copy start signal is sent to the control means 100, the control means 100 causes the electric motor 60 to operate.
(M1) is turned on and the electromagnetic clutch 35 (CL
T1) is urged to rotate the drive roller 28 in the direction indicated by the arrow. When the drive roller 28 rotates, the feeding belt 32 is operated in the direction indicated by the arrow. Also,
When the second document detecting sensor 23 (SW2) detects the document, the feeding clutch 40 is rotated because the electromagnetic clutch 56 (CLT2) is energized. Therefore, the lowest document adhering to the feeding belt 32 and the feeding drum 40 as described above is fed to the downstream side in the conveying direction. In this way, when a document having a large width dimension is placed on the document table 12, that is, when the second document detection sensor 23 (SW2) detects the document, the vacuum separating and feeding means 24 side is provided. The feeding drum 40 disposed on one side is operated, and the lowermost original is fed while being sucked over the entire width direction by the vacuum separating and feeding means 24 and the feeding drum 40. Is reliably prevented. Further, in the illustrated embodiment, when a document having a small width dimension is placed on the document table 12, that is, when the second document detection sensor 23 does not detect the document, the solenoid 468 (SOL
Since 1) is deenergized and the opening / closing valve 46 is closed,
Vacuum chamber 26 of vacuum separating and feeding means 24
The degree of vacuum inside does not decrease. In the illustrated embodiment, when the second document detection sensor 23 (SW2) does not detect the document, the electromagnetic clutch 56 (C
Since LT2) is deenergized and the feeding drum 40 stops, the feeding drum 40 does not rotate without a document above it, so that safety can be ensured.

As described above, the original set on the original table 12 is conveyed onto the transparent plate 8 and subjected to exposure processing, and thereafter, the original table 12 is discharged by the original discharging means.
Put back on. At this time, if there is a document on the document table 12, there is no problem, but if there is no document on the document table 12, the following problem occurs. That is, if the number of originals set on the original table 12 is two, for example, 1
When the first original is exposed and discharged onto the original table 12, the primary and secondary paper feeding operations have already been performed, and there is no second original on the original table 12, There is no document on the table 12. When the first document is discharged with no document on the document table 12, the front end of the document comes into contact with the feeding belt 32 of the vacuum separating and feeding means 24 which is inactive. Since the feeding belt 32 is made of a rubber material, the front end of the document is caught, which may cause the document to break or jam. In order to solve such a problem, the automatic document feeder according to the illustrated embodiment is operated as shown in the flowchart of FIG. The operation procedure of the automatic document feeder at the time of discharging the first document will be described below with reference to the flowcharts of FIGS. 6 and 7.

The control means 100 checks whether or not the first document detection sensor 21 (SW1) is ON, that is, whether or not a document is set on the document table 12 (step S1). If a document is set on the document table 12, the process proceeds to step S2 to check whether or not a copy start signal is sent from the control means 200 of the electrostatic copying machine 2. The operator sends the copy start signal to the operation means 20.
By inputting a copy start signal with the copy start key No. 1, the control means 200 sends it to the control means 100.
If the copy start signal is sent in step S2, the process proceeds to step P0 to execute the above-mentioned subroutine of the primary paper feeding operation for transporting the lowest document set on the document table 12 to the registration roller pair 74, and Then, the process proceeds to step Q0 to execute the subroutine of the secondary paper feeding operation for positioning the original document fed to the nip portion of the registration roller pair 74 at a predetermined position on the transparent plate 8 of the electrostatic copying machine 2.

Next, the control means 100 proceeds to step S3 to check whether or not the document exchange signal is sent from the control means 200 of the electrostatic copying machine 2. This document exchange signal is
When the exposure of the original document conveyed on the transparent plate 8 is completed, it is sent from the control means 200 of the electrostatic copying machine 2 to the control means 100. If there is no original exchange signal in step S3, the exposure operation of the original conveyed on the transparent plate 8 is not yet completed, and the process waits. If there is an original exchange signal, step S3 follows.
4, the electric motors 61 (M2) and 62 (M
3) a conveyor belt mechanism 76 that drives the original document conveying means and a pair of conveying rollers 82 that constitutes the original document discharging means,
84 and the discharge roller pair 86 are operated. As a result, the original document conveyed on the transparent plate 8 and subjected to the exposure process is transported to the original document discharge path 80
Be transported through. When the control means 100 drives and controls the electric motors 61 (M2) and 62 (M3) in step S4, the process proceeds to step S5, and it is determined whether the discharged document detection sensor 800 (SW5) is turned on, that is, the document to be discharged. The front end of the sheet is the discharged document detection sensor 800 (SW5)
Check whether or not the position has been reached. Step S5
If the discharged original detection sensor 800 (SW5) is not turned on in step S4, the front end of the original is detected by the discharged original detection sensor 800 (S
Since it has not reached W5), if the discharged original detection sensor 800 (SW5) is turned on, it is determined that the front end of the original has reached the position of the discharged original detection sensor 800 (SW5), and the control means 100 determines in step S6. And the rotation amount detecting means 620 mounted on the electric motor 62 (M3).
The counting of the pulse signal (PS) from (FG3) is started. Then, the control means 100 proceeds to step S7 to check whether or not the count value (PSN) of the pulse signal (PS) from the rotation amount detection means 620 (FG3) has reached the set value (N1). The set value (N1) is set to the number of pulse signals corresponding to the carry amount from when the front end of the document reaches the position of the discharged document detection sensor 800 (SW5) to immediately before it reaches the document table 12. In step S7, the count value of the pulse signal (PS) (P
If the SN does not reach the set value (N1), wait and wait for the count value (PSN) of the pulse signal (PS) to reach the set value (N1).
If it reaches, the control means 100 proceeds to step S8 to determine whether or not the third document detection sensor 27 (SW3) is OFF, that is, the feeding belt 32 of the vacuum separation feeding means 24 on the document table 12. Check if there is no original on the top. Note that the manuscript table 1
As a means for detecting the presence / absence of a document on the second document, a detection signal of the first document detection sensor 21 (SW1) as a document setting sensor may be used. In step S8, if the third document detection sensor 27 (SW3) is not turned off and there is a document on the document table 12, there is no problem. Therefore, the first document is discharged as it is. In step S8, the third document detection sensor 27 (SW3)
Is OFF, it is determined that there is no document on the document table 12, and the control means 100 proceeds to step S9 to drive the electric motor 60 (M1) and the electromagnetic clutch 35 (CLT1). ). Therefore, the feeding belt 32 of the vacuum separating and feeding means 24 is operated. Therefore, even if the front end of the discharged original comes into contact with the feeding belt 32, the front end of the original is not caught because the feeding belt 32 is moving in the original conveying direction. At this time, the voltage supplied to the electric motor 60 (M1) is controlled so that the moving speed of the feeding belt 32 becomes the same or substantially the same as the conveying speed of the discharged document, and the electric motor 60 (M1) is controlled. It is desirable to control the rotation speed. Generally, the document discharging speed by the discharging roller pair 86 is faster than the document conveying speed of the feeding belt 32. If this speed difference is large, the front end of the discharged document may be caught even if the feeding belt 32 is operated. Therefore, it is desirable to drive and control the electric motor 60 (M1) so that the moving speed of the feeding belt 32 becomes substantially the same as the document discharging speed by the discharging roller pair 86.

In step S9, the electric motor 60 (M
1) while driving the electromagnetic clutch 35 (CLT
If 1) is activated, the control means 100 causes step S1.
In step 0, the discharged original detection sensor 800 (SW5) turns off.
It is checked whether or not F has occurred, that is, whether or not the trailing edge of the discharged document has reached the position of the discharged document detection sensor 800 (SW5). If the discharged original detection sensor 800 (SW5) does not turn off in step S10, the trailing edge of the original has not reached the discharged original detection sensor 800 (SW5).
If F, the trailing edge of the document is the discharged document detection sensor 800.
When the control means 100 determines that it has passed (SW5), the control means 100 proceeds to step S11 and sets the timer 104 (T) to T1. The set time T1 is the time until the trailing edge of the document passes the discharged document detection sensor 800 (SW5) and the discharge roller pair 86, and is, for example, 100 msec.
Is set to In step S11, the timer 10
If 4 (T) is set to T1, the control means 100 proceeds to step S12 and the elapsed time TS after the trailing edge of the document passes the discharged document detection sensor 800 (SW5) reaches the set time T1. Check whether or not the elapsed time T
If S does not reach the set time T1, the document discharge operation is continued, and if the elapsed time TS reaches the set time T1, it is determined that the trailing edge of the document has passed the discharge roller pair 86 and the process proceeds to step S12. , Electric motor 60 (M1), 6
1 (M2) and 62 (M3) are turned off, and the electromagnetic clutch 35 (CLT1) is deenergized.

[0029]

The automatic document feeder according to the present invention is constructed as described above, and when the first document set on the document table and fed by the vacuum separating and feeding means is discharged by the document discharging means. , When the document detection sensor outputs a signal that there is no document on the document table, the feeding motor is driven to operate the feeding belt of the vacuum separation feeding means, so that the front end of the discharged document is caught on the feeding belt. There is no such thing.

Further, according to the present invention, since the control means drives and controls the feeding motor so that the moving speed of the feeding belt becomes substantially the same as the document discharging speed by the document discharging means,
It is possible to reliably prevent the front end of the discharged document from being caught by the feeding belt.

[Brief description of the drawings]

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

FIG. 2 is a plan view of a main part with a part of a document separating / feeding mechanism included in the automatic document feeder shown in FIG. 1 cut away.

FIG. 3 is a cross-sectional view taken along the line AA of the document separating / feeding mechanism shown in FIG.

FIG. 4 is a cross-sectional view taken along line BB of the document separating / feeding mechanism shown in FIG.

5 is a block diagram showing the configuration of control means provided in the automatic document feeder shown in FIG.

6 is a partial flowchart showing the processing procedure of the control means shown in FIG.

FIG. 7 is a partial flowchart showing a processing procedure of the control means shown in FIG.

[Explanation of symbols]

 2: Electrostatic copying machine 4: Automatic document feeder 6: Electrostatic copying machine housing 8: Transparent plate 10: Document regulating member 12: Document table 14: First opening 16: Second opening 18: Pair of guides Groove 20: Width regulating member 21: First original detection sensor (SW1) 23: Second original detection sensor (SW2) 24: Vacuum separation / feeding means 26: Vacuum chamber 27: Third original detection sensor (SW3) 28: drive roller 30: driven roller 32: feeding belt 34: duct 35: electromagnetic clutch (CLT1) 36: suction blower 39: roller driving gear 40: feeding drum 42: duct 46: open / close valve 56: electromagnetic clutch (CLT2) 59: Feed Drum Driving Gear 60: Electric Motor (M1) as Paper Feed Motor 61: Electric Motor (M2) as Conveyor Motor 6 : Electric motor (M3) as discharge motor 62: Intermediate gear 63: Separation air jetting means 64: Set document stopper 66: Discharge document stopper 70: Paper feed roller pair 72: Document carry-in path 74: Registration roller pair 75: Electromagnetic clutch (CLT3) 76: Conveying belt mechanism 80: Original conveying path 82: Conveying roller pair 84: Conveying roller pair 86: Discharging roller pair 88: Extrusion plate 468: Solenoid (SOL1) 600: Rotation amount detecting means (FG1) 610: Rotation Quantity detection means (FG2) 620: Rotation quantity detection means (FG3) 720: Incoming original detection sensor (SW4) 800: Outgoing original detection sensor (SW5)

Claims (2)

[Claims] 1. An original table having an opening at a front portion in the original conveying direction, and an upper surface below the opening of the original table is arranged substantially flush with an upper surface of the original table, and an opening is provided on the upper surface. A vacuum chamber, a feeding belt provided with a plurality of holes wound around the vacuum chamber and operated in the document conveying direction, and air toward the front end of the document placed on the document table. Vacuum separating / feeding means having a separating air jetting means for ejecting, original conveying means for conveying the original fed by the vacuum separating / feeding means onto a transparent plate, and an original on the transparent plate A document discharging unit that discharges onto the table, a feeding motor that drives a feeding belt of the vacuum separating and feeding unit, a conveyance motor that drives the document conveying unit, and a discharge motor that drives the document discharging unit. An original detection sensor that detects the presence or absence of an original on the original table, and a control unit that controls the feeding motor, the conveyance motor, and the discharge motor based on a detection signal from the original detection sensor, The control means drives the feeding motor to feed the vacuum separating and feeding means when the original detection sensor outputs a signal indicating no original when the first original is discharged by the original discharging means. An automatic document feeder, which operates a belt. 2. The automatic document feeder according to claim 1, wherein the control unit drives and controls the feeding motor such that the moving speed of the feeding belt is substantially the same as the document discharging speed of the document discharging unit. apparatus.