JPH08282867A - Automatic document carrying device - Google Patents

Abstract

PURPOSE: To minimize the number of documents fed to a document separating mechanism as much as possible while preventing a jamming by bringing a document fed by a forward feed roller into the frictional surface of a limiting plate forming a forward loosening means, and regulating its movement on the downstream side. CONSTITUTION: The greater part of documents 50 put on a document table and fed by the action of a forward feed roll 40 is regulated in movement by the action of a forward loosening means 59, and only several pieces of the documents on the lower level are apt to move to a separating belt mechanism 66 side. At that time, the document on the top part of several documents moved to the separating belt mechanism 66 side makes contact with the frictional surface 594 of a limiting plate 591, and regulated in the movement to the downstream side. Although the document 50 thus making contact with the frictional surface 594 of the limiting plate 591 is regulated in the movement to the downstream side, 1-3 documents 50 situated under it are carried toward a document separating mechanism 60. Thus, the documents 50 fed to the document separating mechanism 60 can be limited to a minimum number of 1-3.

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 processing machine such as an electrostatic copying machine or an image reader.

[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. In addition, an automatic document feeder for automatically feeding a plurality of documents sequentially to a document processor such as a facsimile or an image reader is widely put into practical use. This type of automatic document feeder is provided with a document table on which a document is placed, a forward feed means for feeding the document placed on the document table, and a forward feed means arranged downstream of the forward feed means. A front separating plate that regulates the movement of the formed original document, and a document that separates and supplies the originals sent by the front feeding means and separated by the front separating plate into a plurality of lower sheets and fed. It has a separation mechanism. The document separating mechanism includes a sheet feeding roller and a separating belt mechanism which is arranged above the sheet feeding roller so as to face the sheet feeding roller and is operated in a direction opposite to the conveying direction. In such a case, a friction method is generally practiced in which the uppermost original is conveyed only by the paper feed roller while the movement in the conveying direction is restricted by the frictional force of the separation belt mechanism. Has been converted.

[0003]

In the document separating mechanism of the friction type, a plurality of sheets are returned between the paper feeding roller and the separating belt mechanism, and therefore a plurality of documents are fed. It is unavoidable that the originals are strongly rubbed with each other, and the originals are rubbed with each other, so that the originals are stained. When the document is fed to the document separating mechanism, the front separating plate arranged upstream of the document separating mechanism regulates the number of documents fed to the document separating mechanism so as not to increase. If the lower edge of the front separating plate is projected downward and the distance between it and the lower guide plate is narrowed in order to minimize the number of documents to be fed to, the lowermost original will also interfere with the front separating plate and jam the paper. Occurs. Therefore, there is a limit to narrowing the distance between the front separating plate and the lower guide plate.

The present invention has been made in view of the above facts, and its main technical problem is to prevent occurrence of paper jam while reducing the frequency of rubbing of originals in the original separating mechanism as much as possible. An object of the present invention is to provide an automatic document feeder including a pre-sorting unit that can reduce the number of documents fed to a document separating mechanism as much as possible.

[0005]

According to the present invention, in order to achieve the above technical object, an original table on which an original is placed and a downstream side of the original table are vertically spaced from each other. An upper guide plate and a lower guide plate that are provided; a forward feed unit that includes a forward feed roller that feeds a document placed on the document table along the upper guide plate and the lower guide plate; Pre-sorting means arranged downstream of the feeding means to regulate the document fed by the front-feeding means,
In an automatic document feeder including a document separating mechanism disposed on the downstream side of the pre-sorting unit, the pre-sorting unit includes:
A lower limit plate which is disposed above the lower guide plate and has a lower end projecting downward from a lower surface of the upper guide plate and which is formed of an elastic member at a predetermined interval from the lower guide plate; There is provided an automatic document feeder, wherein the upstream surface of the limiting plate is formed by a friction surface having a high friction coefficient.

The friction coefficient of the friction surface of the limiting plate is determined by the frictional force F1 between the originals placed on the original table, the frictional force F2 between the limiting plate and the leading edge of the original, and the frictional force on the original table. The relationship between the placed document and the frictional force F3 between the front feed roller is set so as to satisfy F1 <F2 <F3. Further, an automatic document feeder including a deflecting plate that is disposed so as to face the lower end of the limiting plate and is formed of an elastic member that is inclined upward from the upper surface of the lower guide plate toward the downstream side. Will be provided.

[0007]

In the automatic document feeder constructed according to the present invention, the document placed on the document table and fed by the action of the forward feed roller comes into contact with the friction surface of the limiting plate constituting the pre-sorting means. Movement to the downstream side is restricted. Then, one to three lower originals are conveyed toward the original separating mechanism.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of an automatic document feeder constructed according to the present invention will now be described in detail with reference to the accompanying drawings.

FIGS. 1 and 2 show 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 (FIG. 2), which may be a glass plate, is arranged on the upper surface of the housing 6. On one side of the transparent plate 8 (on the left side in FIG. 2), a document regulating member 1 that defines a document setting reference position G
0 is disposed, and the stationary mounting member 12 is disposed on the other side (right side in FIG. 2). An automatic document feeder 4 constructed in accordance with the present invention comprises a housing 6 of an electrostatic copier 2.
Is mounted on the upper surface of the transparent plate 8 so as to be rotatable between a closed position shown by a solid line in FIG. 1 and an open position shown by a chain double-dashed line about a turning axis extending along the rear side edge of the transparent plate 8. Electrostatic copying machine 2
When a document is manually placed on the transparent plate 8, the automatic document feeder 4 is opened to expose the transparent plate 8 and the document is placed at a desired position on the transparent plate 8. The document feeder 4 is closed to cover the transparent plate 8 and the document placed on it. When placing an original on the transparent plate 8, one edge of the original is brought into contact with the leading edge of the original regulating member 10 and the one edge of the original is positioned at the original setting reference position G so that the original is required. Can be positioned in any position. When a document is automatically loaded onto the transparent plate 8 using the automatic document feeder 4 and is automatically discharged from the transparent plate 8, the automatic document feeder 4 is positioned at the closed position.

Continuing the description with reference to FIG. 1, the illustrated automatic document feeder 4 includes a front cover 14 and a rear cover which are arranged at intervals in the front-rear direction (direction perpendicular to the paper surface in FIG. 2). Includes 16. The front cover 14 and the rear cover 16 can be formed of an appropriate synthetic resin. A rear support substrate (not shown) is arranged in the rear cover 16, and such a rear support substrate is provided with a mounting mechanism (not shown) which may have a known form. And is mounted on the upper surface of the housing 6 of the electrostatic copying machine 2 so as to be freely rotatable. Various components of the automatic document feeder 4 are directly or indirectly supported on the rear support substrate. A document placing unit 18 and a document discharge tray 20 are provided between the front cover 14 and the rear cover 16. The document placing means 18 includes a document table 22 extending upwardly from the left end to the right rear end in FIG. 2, and an auxiliary table rotatably mounted at the rear end of the document table 22. It consists of 24. A pair of width regulating members 26 is attached to the document table 22 so as to be movable in the width direction. Such a pair of width regulating members 26 are connected to each other below the document table 22 via a rack and a pinion mechanism (not shown) which are known per se, and they interlock with each other to approach each other. To move in the direction away from each other.
The document discharge tray 20 is disposed below the document placing means 18, and has a document placing surface 28 formed in a mountain shape when viewed from the front-rear direction (direction perpendicular to the paper surface in FIG. 2). A left end cover 30 is provided between the left ends of the front cover 14 and the rear cover 16, and a right end cover 32 is provided between the right ends thereof. The front cover 14
Inside, a safety switch SW1 for detecting the open / closed state of the automatic document feeder 4, a safety switch SW2 for detecting the open / closed state of the left end cover 30, and a right end cover 32.
Is provided with a safety switch SW3 for detecting the open / closed state of the switch, and these switches are provided in series. When the covers are positioned at the closed position and all the switches are closed, an ON signal will be described later as a control means. Output to.

Continuing the description with reference to FIGS. 1 to 4,
A lower guide plate 34 is provided on the downstream side of the document table 22.
The upper guide plate 36 is arranged above the lower guide plate 34 with a predetermined space, and the document carrying-in means 33 is provided with the forward feeding means 38 and the document separating mechanism 60. . The lower guide plate 34 extends downstream from the front end position of the document table 22, and the upper guide plate 36.
Is disposed on the downstream side in the transport direction from the downstream end of the forward feeding means 38. The forward feeding means 38 is used for the lower guide plate 3
4 is provided with a forward feed roller 40 disposed below, and a forward feed pressing unit 44 disposed above the forward feed roller 40. The forward feed roller 40 is formed of a rubber material having a predetermined friction coefficient, and the lower guide plate 3
4 is arranged so as to project slightly upward from an opening 42 formed on the upstream side of 4. The forward feed pressurizing means 44 has a rotating shaft 46 disposed above the forward feed roller 40 in parallel with the forward feed roller 40, and an upper end portion fixed to the rotating shaft 46 and a lower end portion of the original document. A pressure plate 48 that acts on the document 50 placed on the table 22 and inserted on the lower guide plate 34 is provided. The pressurizing plate 48 is formed of an elastic thin plate made of a stainless steel plate in the illustrated embodiment, the upper end thereof is fixed to the rotating shaft 46 by a fixing means such as a screw, and the lower end thereof is the front portion. It is configured to act on the upper surface of the uppermost document 50 placed on the document table 22 at the upper position of the feed roller 40 and press the document 50 against the forward feed roller 40. The rotary shaft 46 that constitutes the forward feed pressurizing means 44 has side plates 51a (only the rear side plate 51a in FIG. 5) provided at the front and rear ends of the support substrate 51 disposed above the forward feed roller 40. (Shown) rotatably supported. The rotation shaft 46 is connected to the solenoid SL1 via the link mechanism 52, and when the solenoid SL1 is biased, it is rotated in the direction indicated by the arrow 56 against the spring force of the return spring 54. , When the solenoid SL1 is deenergized, the return spring 5
It is rotated in the direction shown by the arrow 58 by the spring force of 4. Therefore, the pressure plate 48 attached to the rotating shaft 46
Means that the solenoid SL1 is energized and the rotary shaft 46 is moved to the arrow 56.
When the original 50 inserted in the stationary plate 34 is pressed in the direction shown in FIG. Then, it is separated from the original 50. The forward feeding means 38 configured as described above urges the solenoid SL1 of the forward feeding pressing means 44 to press the original 50 inserted on the stationary plate 34 by the pressing plate 48, and drives the forward feeding roller 40. By doing so, the lowermost original 50 can be sent out by the friction driving force generated at the contact portion between the front feed roller 40 and the lower surface of the lowermost original 50. A document set switch SW4 as a document detection means is arranged on the support substrate 51, and the document set switch SW4 is placed on the document table 22 and the document 50 is placed on the lower guide plate 34. When the document is inserted, the ON signal as the first signal is transmitted to the original table 2
When the document 50 is not placed on the sheet 2, an OFF signal as a second signal is output to the control means described later.

At the upstream end (the right end in FIG. 3) of the upper guide plate 36, there is provided a pre-sorting means 59 for regulating the document fed by the forward feed means 38. Referring to FIG. 5, FIG. 6, and FIG. 7 together with FIG. 3, an inclined portion 361 that extends at an angle slightly upstream of the right angle is formed at the upstream end of the upper guide plate 36. ing. A regulation plate 590 is attached to the back surface of the inclined portion 361 at a position facing the pressure plate 48 by a fixing means such as an adhesive. In the illustrated embodiment, the lower end of the regulation plate 590 is formed so as to project downward from the lower surface of the upper guide plate 36. A restriction plate 591 made of an elastic member is attached to the back surface of the restriction plate 590. The limiting plate 591 will be described in detail with reference to FIG. The limiting plate 591 according to the illustrated embodiment includes a substrate 592 made of a polyethylene terephthalate (PET resin) film (thickness 0.075 mm), and the substrate 592.
And a high-friction sheet 593 having a high-friction coefficient friction surface 594 mounted on one side by an adhesive.
As such a high friction sheet, for example, a non-slip sheet (trade name) manufactured by Nippon Oil Industry Co., Ltd. in which a PET resin sheet is coated with a silicon resin (dynamic friction coefficient:
Based on the American Standard for Material Testing ASTM D-1892 (USA), a load of 2 is applied to the pressed surface of stainless steel.
It is possible to use 1.45) at 00 g. The limiting plate 591, in which the high-friction sheet 593 is attached to one surface of the substrate 592 made of an elastic member, has the double-sided adhesive tape 595 attached to the other surface of the substrate 592, and is adhered to the back surface of the regulation plate 590 by the double-sided adhesive tape 595. To be done. In this way, by mounting the limiting plate 591 on the back surface of the regulating plate 590, the surface of the upstream side of the limiting plate 591 has the high friction sheet 5.
It becomes the friction surface 594 of 93. The restriction plate 591 is the restriction plate 5
In the state of being mounted on 90, the lower guide plate 34 is arranged so as to be inclined downward with a tilt angle α of 70 ° to 80 ° with respect to the upper surface of the lower guide plate 34, and its lower end and the lower part 1.0 mm to 2.0 mm between the upper surface of the side guide plate 34
The gap is provided. The friction coefficient of the friction surface 594 of the high-friction sheet 593 that constitutes the limiting plate 591 is the frictional force F1 between the documents 50 placed on the document table 22, the friction surface 594 of the limiting plate 591, and the document tip. The relationship between the frictional force F2 with the surface and the frictional force F3 between the lowest document of the document 50 placed on the document table and the front feed roller 40 is set so as to satisfy F1 <F2 <F3. Is important.

The front separating means 59 configured as described above
Works as follows: As shown in FIG. 7, the movement of most of the document 50 placed on the document table 22 and fed out by the action of the forward feed roller 40 is regulated by the action of the regulation plate 590, and only the lower few sheets are fed. Tries to move to the separation belt mechanism 66 side. At this time, the uppermost document of the several documents that is about to move to the separation belt mechanism 66 side has the upper surface of the leading end portion of the limiting plate 591.
The frictional surface 594 is contacted, and the movement to the downstream side is restricted. That is, the friction coefficient of the friction surface 594 of the limiting plate 591 is
Friction force F between the friction surface 594 of the limiting plate 591 and the front end surface of the document
2 is larger than the frictional force F1 between the documents 50 as described above, and the frictional force F between the lowest document and the forward feed roller 40.
Since it is set to be smaller than 3, when two or more originals are to be conveyed, the uppermost original comes into contact with the friction surface 594 of the limiting plate 591 and its downstream movement is restricted. To be done. In this way, the movement of the original that comes into contact with the friction surface 594 of the limiting plate 591 is restricted to the downstream side, but the first to three originals below the original are separated from the original separation mechanism 6.
It is transported toward 0. Therefore, the number of documents fed to the document separation mechanism 60 can be limited to a very small number of one to three.

Next, another embodiment of the pre-sorting means 59 is shown in FIG.
Will be described with reference to. Pre-sorting means 59 in this embodiment
Is a deflection plate 597 made of an elastic member facing the lower side of the limiting plate 591, and
It is arranged so as to be inclined upward toward the downstream side with an inclination angle β of 5 ° to 25 °. In order to mount the deflecting plate 597 on the lower guide plate 34, a part of the lower guide plate 34 is cut and raised downward so as to be 15 ° to 25 ° to the upper surface of the lower guide plate 34. A mounting portion 341 formed with an inclination angle β is provided. The deflection plate 597 is
For example, it is formed of a PET resin film and mounted on the mounting portion 341 with a double-sided adhesive tape or an adhesive. In this way, by arranging the inclined deflecting plate 597 which is made of an elastic member and faces the lower side of the limiting plate 591 and is directed upward toward the downstream side, a gap between the lower end of the limiting plate 591 and the lower guide plate 34 is provided. When several originals try to pass over one another, the originals are deflected upward by the deflecting plate 597 and pressed against the limiting plate 591. Therefore, the uppermost original document that is about to pass between the lower end of the limiting plate 591 and the lower guide plate 34 in an overlapping manner is the friction surface 594 of the limiting plate 591.
The movement of the document to the document separating mechanism 60 is restricted, so that the number of documents conveyed toward the document separating mechanism 60 can be surely reduced.

The document separating mechanism 60 arranged on the downstream side of the forward feeding means 38 is arranged below the lower guide plate 34 and is fixed to the stationary guide plate 34, as shown in FIGS. 3 and 4. A plurality of roller portions 641 (up to five in the illustrated embodiment) that are projected upward through the formed opening 62.
Paper feed roller 64 having a number of pieces) and the upper guide plate 36
And a separation belt mechanism 66 which is disposed above the paper feed roller 64 and is projected upward through an opening 77 formed in the upper guide plate 36. The separation belt mechanism 66 includes the upper guide plate 3
6, a driving roller 67 as a first roller disposed on the upstream side of the driving roller 67, and a second roller disposed in parallel on the downstream side of the driving roller 67 in the transport direction at a distance. A driven roller 68, and a separation belt 69 wound around the drive roller 67 and the driven roller 68.
The drive roller 67 is made of synthetic resin and includes a plurality of roller portions 671 (five in the illustrated embodiment). The driven roller 68 is also made of synthetic resin, and has a plurality of roller portions 681 corresponding to the roller portion 671 of the driving roller 67 (in the illustrated embodiment, 5).
Individual). The separating belt 69 is made of a synthetic rubber material, and a plurality of separating belts 69 are provided corresponding to the plurality of roller portions 671 of the driving roller 67 and the plurality of roller portions 681 of the driven roller 68 (in the illustrated embodiment, respectively). 5) and corresponding roller portions 671
And a roller portion 681. The plurality of separation belts 69 are alternately arranged with the plurality of roller portions 641 of the paper feed roller 64, and protrude downward through an opening 74 formed in the upper guide plate 36. The front feed roller 40, the paper feed roller 64, and the separation belt mechanism 66 are driving means 78 including an electric motor M1 and a transmission mechanism 76 such as a gear mechanism or an electric belt mechanism.
Are driven to rotate in the directions indicated by arrows 79, 80 and 82, respectively. Therefore, the forward feed roller 40 and the paper feed roller 64 are rotated in the document transport direction, and the separation belt mechanism 66 is operated in the direction opposite to the document transport direction. The electric motor M1 is equipped with a rotation amount detecting means FG1 such as a rotary encoder or a frequency generator which constitutes a document conveying amount detecting means, and outputs a pulse signal which is a detection signal thereof to a control means which will be described later. .

The document separating means 60 constructed in this way
Works as follows. That is, the forward feed roller 40
The original fed out by the above is regulated by the pre-sorting means 59 and one to three sheets are fed to the original separating mechanism 60. If the number of originals fed to the original separating mechanism 60 is one, the originals are directly fed to the original carry-in path 98 by the action of the paper feed roller 64. On the other hand, when there are two originals fed to the original separating mechanism 60, the separating action by the paper feeding roller 64 rotating in the conveying direction and the separating belt 69 moving in the opposite direction to the conveying direction. Thus, only the lowermost original is fed to the original carry-in passage 98. The paper feed roller 6
In the separating action of 4 and the separation belt 69, rubbing of the originals occurs, and when the number of times of the rubbing increases, the dirt of the original becomes remarkable. However, in the illustrated embodiment, the number of originals fed by the front feed roller 40 is regulated by the limiting plate 591 which constitutes the front separating means 59 as described above, so that the originals rub against each other. It is possible to reduce the frequency of contact and reduce the contamination of the documents due to the rubbing of the documents.

Between the forward feeding means 38 and the document separating mechanism 60, as shown in FIGS. 2 to 4, the document 5 placed on the document table 22 and inserted on the lower guide plate 34 is inserted.
A document stopper 84 configured to be operable is provided at an operation position that restricts the insertion of 0 to the document separation mechanism 60 side and a retracted position that allows movement to the document separation mechanism 60 side. The document stopper 84 is disposed below the lower guide plate 34, and its base end is disposed at a position upstream of the forward feed roller 40 in parallel with the axis of the forward feed roller 40 at a distance. The shaft 86 is fixed to the shaft 86, and its tip is arranged through an opening formed in the lower guide plate 34. The rotating shaft 86 to which the document stopper 84 is attached is operated by the stopper driving means 87. The stopper drive means 8
Reference numeral 7 includes a latch solenoid SL2 and a link mechanism 88 that connects the plunger 90 of the latch solenoid SL2 and the rotating shaft 86. The latch solenoid SL2 may be a well-known one and has a permanent magnet, a suction coil and a spacing coil inside, and when the suction coil is energized, the plunger 90 is attracted, and in this state, the magnetic force of the permanent magnet causes the plunger to move. Even if 90 is sucked and the suction coil is deenergized, the plunger 90 is held in the suctioned state.
Further, when separating the plunger 90 from the suction state,
After the spacing coil is urged to separate the plunger 90 against the magnetic force of the permanent magnet, the spacing state of the plunger 90 is maintained even if the spacing coil is de-energized. Therefore, when the suction coil of the latch type solenoid SL2 is biased to attract the plunger 90, the rotary shaft 86 is rotated in the direction shown by the arrow 92, and the document stopper 84 attached to the rotary shaft 86 is moved to the position shown in FIG. In the retracted position shown by the solid line. Further, when the separation coil of the latch solenoid SL2 is urged to separate the plunger 90, the rotary shaft 86 is rotated in the direction shown by the arrow 94, and the document stopper 84 attached to the rotary shaft 86 is moved to the position shown in FIG. At 2
It is located at the operating position indicated by the dashed line and is held by the spring force of the return spring 96. A shield plate 85 is attached to the document stopper 84, and a stopper position detection means SW5 is arranged at a position facing the document stopper 84 when the document stopper 84 is positioned at the retracted position shown by a solid line. The stopper position detecting means SW5 is provided with a light emitting element and a light receiving element, and when the document stopper 84 is positioned at the working position shown by the chain double-dashed line, it is turned on as a first signal.
When the document stopper 84 is positioned at the retracted position indicated by the solid line and the shield plate 85 is positioned between the light emitting element and the light receiving element, an OFF signal as a second signal is output to the control means described later.

Continuing the description with reference to FIGS. 2 and 9, the conveyor belt mechanism 100 is provided below the document placing means 18.
Is provided. The conveyor belt mechanism 100 that constitutes the conveyor means includes a driving roller 102 and a driven roller 10 which are arranged at intervals in the conveying direction (left and right direction in FIG. 2).
4, endless belt 106 wound around these, rolling rollers 105a, 105b, 105c, 105d disposed between driving roller 102 and driven roller 104,
105e is included. The lower running portion of the endless belt 106 extends along the transparent plate 8 of the electrostatic copying machine 2, and a document conveyance path 108 is defined between the two. A document carrying-in path 98 is formed between the document carrying path 108 and the document separating means 60. This document carry-in path 98 is defined between the inner guide plate 110 and the outer guide plate 112. A pair of registration rollers 114 is arranged in the original carry-in path 98. The registration roller pair 114
Is composed of a driving roller 116 and a driven roller 118. A reflection type optical document detector SW6 including a light emitting element and a light receiving element is arranged upstream of the registration roller pair 114 in the document carry-in path 98, and the document detector SW6 is provided in the document carry-in path 98. The document 50 passing therethrough is detected, and the detection signal is sent to the control means described later. The drive roller 102 of the conveyor belt mechanism 100 and the drive roller 116 of the registration roller pair 114 are rotationally driven by a drive unit 120 including an electric motor M2 capable of forward / reverse rotation and a transmission mechanism 118 such as a gear mechanism or a belt mechanism. . The driving roller 116 of the pair of registration rollers 114 includes the transmission mechanism 118 and the electromagnetic clutch C.
It is connected via L1. Also, the electric motor M
A rotation amount detecting means FG2 such as a rotary encoder or a frequency generator which constitutes the document conveying amount detecting means is attached to 2 and outputs a pulse signal which is a detection signal thereof to a control means which will be described later.

A document reversing / discharging means 128 is provided on the right side of the document conveying path 108. The document reversing / discharging means 128 is provided with a first document carrying-out path 130, and the first document carrying-out path 130 is provided between the reversing roller 134 and the outer guide plates 136 and 138 which constitute the document reversing and conveying means. It is prescribed. It should be noted that three driven rollers 135a, 135b, 135c are arranged on the outer periphery of the reversing roller 134 in a pressed state. The first original carry-out path 130
The second document carry-out path 140 and the document reversing path 1 are provided on the downstream side of
42 are provided in a branched manner, and a branch control plate 144 is disposed in this branch portion. Second document carry-out path 140
Is defined between the branch control plate 144 and the outer guide plate 146. At the downstream end of the second document carry-out path 140,
A discharge roller pair 152 including a driving roller 148 and a driven roller 150 is arranged. A reflection type optical document detector SW7 including a light emitting element and a light receiving element is provided in the second document carry-out path 140, and the detector SW7 is provided.
Detects the document 50 passing through the second document carry-out path 140 and sends the detection signal to the control means described later. The reversing path 142 includes a reversing roller 134 and a branch control plate 144.
And the outer guide plate 154, and the downstream end thereof is formed so as to face the downstream end of the document conveying path 108. A reflection type optical document detector SW8 including a light emitting element and a light receiving element is arranged in the document reversing path 142, and the detector SW8 detects the document 50 passing through the document reversing path 142, The detection signal is sent to the control means described later. The branch control plate 144 has a shaft 15 at an intermediate portion.
6 and is operated by the solenoid SL3. When the solenoid SL3 is deenergized, it is positioned at the position indicated by the solid line in FIG. 2 by the spring force of the return spring 158.
Is biased against the spring force of the return spring 158, it is positioned at the position indicated by the chain double-dashed line in FIG. Therefore, the document conveyed through the first document carry-out path 130 is sent to the second document carry-out path 140 when the solenoid SL3 is deenergized, and the document reverse path when the solenoid SL3 is energized. It is designed to be sent to 142. The reversing roller 134 and the discharging roller pair 152
The drive roller 148 constituting the motor is constituted by an electric motor M3 and a drive means 162 composed of a transmission mechanism 160 such as a gear mechanism or an electric belt mechanism, and is indicated by arrows 164 and 166, respectively.
It is driven to rotate in the direction indicated by. The electric motor M3 has a rotation amount detecting means FG such as a rotary encoder or a frequency generator which constitutes a document conveying amount detecting means.
3 is attached and outputs a pulse signal, which is a detection signal thereof, to the control means described later.

The automatic document feeder has a control means 200 shown in FIG. The control means 200 is composed of a microcomputer, and has a central processing unit (CPU) 201 that performs arithmetic processing according to a control program.
A read-on memory (ROM) 202 for storing a control program and a control map, a readable / writable random access memory (RAM) 203 for storing calculation results, a timer 204, an input interface 205 and an output interface 206 are provided. There is. The input interface 205 of the control means 200 configured as described above
The safety switches SW1, SW1 and SW3, the document setting switch SW4, the stopper position detecting means SW5,
Detection signals are input from the reflection type optical detectors SW6, SW7, SW8 and the rotation amount detecting means FG1, FG2, FG3, etc., and the electric motors M1, M2, M3, solenoids SL1, SL3, latch type solenoids are output from the output interface 206. A control signal is output to SL2 and electromagnetic clutch CL1. In addition, the control means 200 controls the electrostatic copying machine 2
Is connected to the control means 210, and control signals are exchanged between the two. An operation unit 220 and a display unit 230 are connected to the control unit 210 of the electrostatic copying machine 2. As shown in FIG. 1, the operating means 220 is arranged on the front upper surface of the electrostatic copying machine 2 and is provided with copy operation operation keys such as a copy start key, a copy number specifying key, a double-sided copy specifying key, and a copy operation stop key. Then, the copy information is input to the control means 210 of the electrostatic copying machine 2. Display means 2
Like the operation means 220, the numeral 30 is arranged adjacent to the operation means 220 on the front upper surface of the electrostatic copying machine 2 and displays copy information, failure information, and the like.

The automatic document feeder equipped with the document separating mechanism according to the illustrated embodiment is configured as described above, and its operation procedure will be described below with reference to the flow charts shown in FIGS. 11 to 16. 11 to 13 are main routines, FIG. 14 is a primary paper feed subroutine, and FIG.
Shows a secondary paper feed subroutine, and FIG. 16 shows a reverse paper feed subroutine.

In the main routine shown in FIGS. 11 to 13, the control means 200 first checks in step S1 whether all of the safety switches SW1, SW2 and SW3 are turned on. That is, the automatic document feeder 4, the left end cover 30, and the right end cover 3
This is a check for prohibiting the operation of the automatic document feeder 4 when any one of them is opened, which is dangerous if the automatic document feeder 4 operates in the state where 2 is opened. Therefore, in step S1, the safety switch SW
If any one of the switch 1, switch SW2 and switch SW3 is OFF, wait until the cover is positioned at the closed position. If all the switches are ON, the process proceeds to step S2, and the document setting switch SW4 is ON. It is confirmed whether or not there is any, that is, whether or not a document is placed on the document table 22. Original set switch SW4 is ON
If not, it is determined that the document is not placed on the document table 22, and the process returns to step S1. When the document set switch SW4 is turned on in step S2, it is determined that the document is placed on the document table 22, the process proceeds to step S3, and the control unit 20 is operated.
0 checks whether a copy start signal is sent from the control means 210 of the electrostatic copying machine 2. This copy start signal is sent from the control means 210 to the control means 200 when the operator inputs the copy start signal with the copy start key of the operation means 220. Therefore, if the copy start signal has not been sent, there is no need for copying, and the process returns to step S1. When the copy start signal is sent in step S3, the process proceeds to step S4, and the control means 200 determines whether or not the stopper position detection means SW5 is ON, that is, the document stopper 84 is at the operating position shown by the chain double-dashed line in FIG. Check if it is positioned. This is because when the document 50 is placed on the document table 22 and inserted on the stationary plate 34 in a state where the document stopper 84 is not positioned at the operating position shown by the chain double-dashed line in FIG. It goes over the lower end of the plate 59 and reaches the document separating mechanism 60,
Since there is a risk that the documents will be double-fed, the document stopper 84 is positioned at the operating position to check whether the document 50 is set at the predetermined insertion position. If the stopper position detecting means SW5 is not turned on in step S4, the document 50 may reach the document separating mechanism 60 and be multi-fed. Therefore, the document carrying-in operation is not started, and the control means 200 proceeds to step S5. A jam alarm is displayed on the display unit 230 via the control unit 210 of the electrostatic copying machine 2. As a result, it is possible to prevent the document from being double-fed when the document 50 is placed on the document table 18 and inserted onto the stationary plate 34 in a state where the document stopper 84 is not positioned at the operating position.

When the stopper position detecting means SW5 is turned on in step S4, that is, the document stopper 84 is positioned at the working position, the control means 200 proceeds to step S6 to drive the electric motor M2 in the forward direction to convey the sheet. In addition to operating the belt mechanism 100, the electric motor M3 is driven to operate the reversing roller 134 and the discharge roller 148 to discharge any original left on the transparent plate 8. Further, the control means 200 has step S6.
Then, the latch type solenoid SL2 is turned on (the latch type solenoid biases the suction coil when attracting the plunger and the spacing coil when separating the plunger. Is turned on when sucking, and turned off when separating the plungers.) That is, the latch type solenoid SL2
And the original stopper 84 is positioned at the retracted position shown by the solid line in FIG. Thus, the electric motor M2, the electric motor M3, and the latch type solenoid S
While activating L2, the control means 200 sets the timer T to T1. The set time T1 is, for example, 100
It is set to msec. Next, the control means 200 checks whether the elapsed time T0 after setting the timer T to T1 has reached the set time T1 (step S
7) If the elapsed time T0 has not reached the set time T1, the process proceeds to step S8 and the stopper position detecting means SW
5 is OFF, that is, whether the document stopper 84 is positioned at the retracted position shown by the solid line in FIG. In step S8, stopper position detecting means S
If W5 does not turn off, the process returns to step S7, and checks until the elapsed time T0 reaches the set time T1. If the stopper position detection means SW5 does not turn off even after the set time T1 elapses, the control means 200 The operation of the document carry-in means 33 is prohibited, and the process proceeds to step S9, where the document stopper 8 is passed through the control means 210 of the electrostatic copying machine 2.
It is displayed on the display means 230 that 4 is abnormal. This abnormality display allows the operator to know that the latch solenoid SL2 or the link mechanism 88 that constitutes the stopper driving means 87 is out of order. If the stopper position detection means SW5 is turned off in step S8, the process proceeds to step S10 shown in FIG. 12 to clear the timer, and further proceeds to step P0 to execute the primary paper feed subroutine.

Next, the primary paper feed subroutine shown in FIG. 14 will be described. In step P1, the control means 200 turns on and drives the electric motor M1 of the document feeding means, and energizes the solenoid SL1 to place the pressure plate 48 on the document table 22 and the document 50 inserted on the stationary plate 34. The original is pressed against the upper surface of the. Therefore, when the forward feed roller 40 is rotationally driven by driving the electric motor M1, the original 50 is fed by the frictional conveyance force generated at the contact portion between the forward feed roller 40 and the lower surface of the lowest original 50. It is sent toward the document separating mechanism 60. When the electric motor M1 is driven, the paper feed roller 64 and the drive roller 67 of the separation belt mechanism 66 that constitute the document separation mechanism 60 together with the forward feed roller 40 are rotationally driven, and the document separation mechanism 60 is operated. . The movement of most of the document fed by the front feed roller 40 is regulated by the action of the regulation plate 590, and only the lower few sheets try to move to the separation belt mechanism 66 side. At this time, the uppermost document of the several documents that is about to move to the separation belt mechanism 66 side has its top surface in contact with the friction surface 594 of the limiting plate 591 and is restricted from moving to the downstream side. , One to three original documents below the original document are conveyed toward the original document separating mechanism 60. Then, even if a plurality of documents are conveyed toward the sheet feeding roller 64, the original is separated by the sheet feeding roller 64 rotating in the conveying direction and the separation belt 69 moving in the opposite direction to the conveying direction. Due to the action, only the lowermost original is fed into the original carry-in path 9
Delivered to 8. In this way, when the document on the document table 22 is fed to the document carry-in path 98, the control means 200
It is checked whether or not the detector SW6 is turned on, that is, whether or not the leading edge of the document fed to the document carry-in path 98 reaches the detector SW6 (step P2). If the detector SW6 is not turned on in step P2, wait for the detector SW6.
If is turned on, the control means 200 sets the timer T to T2 (step P3). This set time T2 is set to 25 msec, for example. Next, the control means 20
0 checks whether or not the elapsed time T0 after setting the timer T to T2 has reached the set time T2 (step P4). If the elapsed time T0 has not reached the set time T2, wait for the original When the conveyance is continued and the elapsed time T0 reaches the set time T2, the process proceeds to step P5, the electric motor M1 and the solenoid SL1 are turned off, and the document feeding operation is stopped. By this primary paper feeding operation, the document feed-in path 9 is moved by the forward feed roller 40 and the document separating mechanism 60.
The document fed to No. 8 is brought into a state where its front end is brought into contact with the nip portion of the registration roller pair 114 in the inoperative state, and the primary sheet feeding is completed.

Returning again to the main routine shown in FIG. 12, when the primary sheet feeding is completed as described above, the control means 200 proceeds to step Q0 to execute the secondary sheet feeding subroutine. The secondary paper feed subroutine will be described with reference to FIG. In step Q1, the control means 200 turns on the electromagnetic clutch CL1 mounted on the driving roller 116 of the registration roller pair 114 to energize it. When the electromagnetic clutch CL1 is energized, the electric motor M2 is already driven in the normal direction, so that the drive roller 116 of the registration roller pair 114 is rotationally driven. Therefore, in the primary sheet feeding, the document fed to the nip portion of the registration roller pair 114 is transported toward the document transport path 108 extending along the transparent plate 8 of the electrostatic copying machine 2, and further, The transparent belt 8 is transported from the left side (one end) to the right side (the other end) in FIG. Next, the control means 200 detects the detector S arranged in the document carry-in path 98 in step Q2.
Whether W6 is OFF, that is, the trailing edge of the document is the detector SW
6 is checked, and the detector SW6 is OF
If it is not F, the process waits. If the detector SW6 is turned off, it is judged that the trailing edge of the original has passed the detector SW6, and the process proceeds to step Q3. Check whether or not This double-sided copy signal is input to the control means 210 of the electrostatic copying machine 2 by the operator using the double-sided copy designation key of the operation means 220, and is sent from the control means 210 to the control means 200 based on this input signal. If there is a double-sided copy signal in step Q3, the flow advances to step R0 to execute a reverse paper feed subroutine. This reverse paper feed subroutine will be described later. If there is no double-sided copy signal in step Q3, the process proceeds to step Q4 to start counting the pulse signal PSB from the rotation amount detecting means FG2 mounted on the electric motor M2 of the conveyor belt mechanism 100. Step Q
When the pulse signal PSB is started to be counted at 4, the control means 200 proceeds to step Q5 and checks whether the pulse signal PSB has reached the set pulse number PS1. The set pulse number PS1 is the pulse number corresponding to the rotation amount of the electric motor M2 corresponding to the document conveyance amount from the detector SW6 to the document setting reference position G in FIG. If the pulse signal PSB does not reach the set number of pulses PS1 in step Q5, wait and continue conveyance,
When the pulse signal PSB reaches the set number of pulses PS1, it is determined that the trailing edge of the document has reached the document setting reference position G, the process proceeds to step Q6, and the electric motor M2 is turned off.
After that, the operation of the conveyor belt mechanism 100 is stopped. At the same time, the electromagnetic clutch CL1 is turned off, and the count of the pulse signal PSB from the rotation amount detection means FG2 is cleared. Next, in step Q7, the control means 200 again outputs the pulse signal P from the rotation amount detection means FG2.
Start SB counting. This is because even if the electric motor M2 is turned off, the drive shaft of the electric motor M2 does not immediately stop but slightly rotates due to inertia. Therefore, the rear end of the original is conveyed to the position advanced by overrunning the original setting reference position G, that is, the right side of the original setting reference position G in FIG. And this transport amount (overrun amount)
This is for detecting. If the counting of the pulse signal PSB from the rotation amount detection means FG2 is started in step Q7, the control means 200 causes the rotation angle detection means FG2.
Then, it is confirmed whether or not the pulse signal PSB from 0 has become zero (0), that is, whether or not the electric motor M2 has surely stopped (step Q8). If it is confirmed in step Q8 that the pulse signal PSB from the rotation amount detecting means FG2 has become zero (0), the process proceeds to step Q9 and the control means 20
0 is the number P of pulses from the rotation amount detecting means FG2 until the electric motor M2 is reliably stopped, that is, the pulse signal PSB from the rotation amount detecting means FG2 becomes zero (0).
S2 is stored in the random access memory (RAM) 203 as an overrun amount, and the count of the pulse signal PSB from the rotation amount detecting means FG2 is cleared. Next, the control means 200, in step Q10,
The electric motor M2 is reversely driven to reversely operate the conveyor belt mechanism 100, and the counting of the pulse signal PSB from the rotation amount detecting means FG2 mounted on the electric motor M2 is started. When the pulse signal PSB from the rotation amount detecting means FG2 is started to be counted in step Q10, the process proceeds to step Q11, and the control means 200 determines whether or not the pulse signal PSB has reached the pulse number PS2 corresponding to the overrun amount. Check. Step Q11
In the case where the pulse signal PSB does not reach the pulse number PS2 corresponding to the overrun amount, wait and continue the conveyance,
When the pulse signal PSB reaches the number of pulses PS2 corresponding to the overrun amount, it is determined that the trailing edge of the document has reached the document setting reference position G, and the process proceeds to step Q12.
The electric motor M2 is turned off to stop the operation of the conveyor belt mechanism 100. Further, the control means 200 outputs a print signal, that is, an exposure start preparation completion signal to the control means 210 of the electrostatic copying machine 2.

Next, the reverse sheet feeding operation will be described based on the reverse sheet feeding subroutine shown in FIG. Control means 20
In step R1, the electric motor M3 is turned on to rotationally drive the reversing roller 134 in step R1, and the solenoid SL3 for controlling the operation of the branch control plate 144 is turned on and energized. When the solenoid SL3 is energized, the branch control plate 1
Since 44 is positioned at the position indicated by the chain double-dashed line in FIG. 2, the document conveyed by the conveyor belt mechanism 100 and the reversing roller 134 is located on the left side (one end in FIG. The sheet is conveyed toward the right side (the other end) from the section) and is further sent to the document reversing path 142 through the first document unloading path 130. In this way, when the electric motor M3 and the solenoid SL3 are operated to convey the document to the document reversing path 142, the control means 200 causes the document detector S arranged in the reversing path 142.
Whether or not W8 is turned on, that is, the front end of the document is the document detector S
It is checked whether W8 has been reached (step R2), and if the document detector SW8 is not turned on, the process waits, and if the detector SW8 is turned on, the process proceeds to step R3 to reverse the electric motor M2 of the conveyor belt mechanism 100. The rotation amount detection means FG3 mounted on the electric motor M3 that drives the reverse belt 134 while driving the conveyor belt mechanism 100 in reverse.
The counting of the pulse signal PSC from is started. If the pulse signal PSC from the rotation amount detecting means FG3 is started to be counted in step R3, the control means 200 proceeds to step R4 and the pulse signal PSC is set by the set pulse number P.
It is checked whether or not S3 (first predetermined carry amount) has been reached. The set number of pulses PS3 is the conveyor belt mechanism 100.
Is set to the document conveyance amount (pulse number) by the reversing roller 134 corresponding to the time from when the electric motor M2 is reversely driven to when the rotation speed is stabilized. The document thus conveyed by the reversing roller 134 is introduced to the right side (the other end portion) of the document conveyance path 108 in FIG. 2 and is conveyed to the left side (the one end portion) by the conveyance belt mechanism 100. If the pulse signal PSC does not reach the set pulse number PS3 in step R4, wait and wait for the pulse signal PS.
If C reaches the set pulse number PS3, step R5
To start the positioning control of the electric motor M2 of the conveyor belt mechanism 100, and the pulse signal PS from the rotation amount detecting means FG2 mounted on the electric motor M2.
Count B starts counting. Note that the positioning control means that when the front end of the document conveyed by the conveyance belt mechanism 100 approaches the document setting reference position G in FIG. 2, the rotation speed of the electric motor M2 is reduced to set the pulse signal PSB to the set pulse number PS4 (second When the electric motor M2 is turned off and the original document does not overrun the original document setting reference position G due to the inertial force, control is performed. When the counting of the pulse signal PSB is started, the process proceeds to step R6, and the control means 200 causes the pulse signal PSB to have the set pulse number PS4 (second
It is checked whether or not the predetermined transport amount has been reached. The set pulse number PS4 is the number of pulses corresponding to the amount of document transportation for transporting the front end of the document sent to the transport belt mechanism 100 to the document setting reference position G by the transport belt mechanism 100 when the counting of the pulse signal PSB is started. Is. When the pulse signal PSB does not reach the set pulse number PS4 in step R6, the conveyance is continued after waiting, and when the pulse signal PSB reaches the set pulse number PS4, the front end of the document reaches the document setting reference position G. Then, the process proceeds to step R7, the electric motor M2 is turned off, and the operation of the conveyor belt mechanism 100 is stopped. At the same time, the electric motor M3 is turned off to stop the operation of the reversing roller 134 and the discharge roller 148, and the solenoid SL3 is turned off to deenergize the branch control plate 144.
Position at the position indicated by the solid line in. Further, the control means 200 outputs a print signal, that is, an exposure start preparation completion signal to the control means 210 of the electrostatic copying machine 2.

Next, returning to the main flow of FIG. 12, description will be made. After executing the primary paper feed subroutine P0, the secondary paper feed subroutine Q0, and the reverse paper feed subroutine R0 as described above, the control means 200 determines in step S11 whether the document set switch SW4 is ON, that is, the document table 22. Check if there is any document left on top. When the document set switch SW4 is turned on, the control means 200 sets a document flag (step S1).
2) The primary paper feed subroutine P0 is executed again. The primary paper feed subroutine P0 is performed while the original document previously conveyed onto the transparent plate 8 is exposed. When the primary paper feed subroutine P0 is executed again in this way, the control means 200 proceeds to step S13 as shown in FIG. 13 to check whether or not a document replacement signal is sent from the control means 210 of the electrostatic copying machine 2. Confirm. This document exchange signal is transmitted from the control unit 210 of the electrostatic copying machine 2 to the control unit 200 when the exposure of the document previously conveyed on the transparent plate 8 is completed.
Sent to If there is a document exchange signal in step S13, the process proceeds to step S14, in which the electric motor M2 is driven in the forward direction to operate the conveyor belt mechanism 100, and the electric motor M3 is driven to operate the reversing roller 134 and the discharge roller 148. The original is discharged on the transparent plate 8 which has been exposed by being rotated. The original document on the transparent plate 8 that has been exposed by this discharging operation is conveyed rightward on the transparent plate 8 in FIG.
It is conveyed to the second document carry-out path 140 through 0. When the electric motor M2 and the electric motor M3 are driven to start the document discharge operation, the control means 200 proceeds to step S15, and the document detector S arranged in the second document carry-out path 140.
Whether W7 is once turned on and then turned off, that is, the trailing edge of the document conveyed to the second document discharge path 140 is the detector SW.
7 is checked, and if the document detector SW7 is once turned on and not turned off, wait, and if the document detector SW7 is turned on and then turned off, the trailing edge of the document is the document detector. Upon determining that the signal has passed SW7, the control means 200 proceeds to step S16 and sets the timer T to T3. This set time T3 is the time from when the trailing edge of the document passes the document detector SW7 to when it passes the discharge roller 148, and is set to, for example, 100 msec.
If the timer T is set to T3 in step S16, the control means 200 proceeds to step S17 and the elapsed time T0 after the trailing edge of the document passes the document detector SW7.
Has reached the set time T3, and if the elapsed time T0 has not reached the set time T3, the document discharge operation is continued, and if the elapsed time T0 has reached the set time T3, the trailing edge of the document is When it is determined that the discharge roller 148 has been passed, the process proceeds to step S18, the electric motor M3 is turned off, and the operations of the reversing roller 134 and the discharge roller 148 are stopped. The exposed document thus discharged from the discharge roller 148 is discharged onto the document discharge tray 20. Next, the control means 200 proceeds to step S19 to check whether or not the original flag is set, and if the original flag is set, it is judged that the next original has already completed the primary paper feeding. Then, the process goes to the secondary paper feed subroutine Q0. If the document flag is not set in step S19, the process proceeds to step S20, it is determined that there is no document that is primarily fed, the electric motor M2 is turned off, and the operation of the transport belt mechanism 100 is stopped. After that, the control means 200 returns to the step S1 and executes the steps. If there is no original exchange signal in step S13, the flow advances to step S21 to check whether a double-sided copy signal has been sent. If the double-sided copy signal has not been sent, the procedure returns to step S13.
If the double-sided copy signal has been sent, the process proceeds to step S22, in which the electric motor M2 of the conveyor belt mechanism 100 is driven in the forward direction, the electric motor M3 driving the reversing roller 134 is turned on, and the reversal sheet feeding subroutine R0 is performed. Move to.

Incidentally, the step S11 in FIG.
If the original set switch SW4 is not turned on in step S23, it is determined that there is no original to be copied on the original table 22, the process proceeds to step S23, the original flag is cleared, and the latch solenoid SL2 is turned off. , The plunger is operated in the direction of separating it to position the document stopper 84 at the operating position indicated by the chain double-dashed line in FIG. At the same time, the control means 200 sets the timer T to T4 in order to diagnose the failure of the latch solenoid SL2 and the link mechanism 88 which form the stopper drive means 87. The set time T4 is set to 100 msec, for example. Next, the control means 200 checks whether the elapsed time T0 after setting the timer T has reached the set time T4 (step S24), and the elapsed time T0.
Does not reach the set time T4, step S2
5, whether the stopper position detection means SW5 is ON,
That is, it is confirmed whether or not the document stopper 84 is positioned at the operating position indicated by the chain double-dashed line in FIG. If the stopper position detecting means SW5 is not turned on in step S25, the process returns to step S24, and a check is made until the elapsed time T0 reaches the set time T4. Even after the set time T4 is passed, the stopper position detecting means SW5 is turned on.
If not, the process proceeds to step S26 to display on the display means 230 that the document stopper 84 is abnormal.
This abnormality display allows the operator to know that the latch solenoid SL2 or the link mechanism 88 that constitutes the stopper driving means 87 is out of order.

[0029]

The automatic document feeder according to the present invention is constructed as described above, and is arranged between the forward feeding means provided with the forward feeding roller for feeding the document placed on the document table and the document separating mechanism. The front separating means is a restriction plate which is disposed above the lower guide plate and has a lower end which projects downward from the lower surface of the upper guide plate and which is formed of an elastic member at a predetermined interval from the lower guide plate. Since the upstream surface of the limiting plate is formed of a friction surface having a high friction coefficient, the original placed on the original table and fed by the front feed roller is regulated by the limiting plate that constitutes the front separating means. Then, 1 to 3 sheets are fed to the document separating mechanism. Therefore, the frequency of rubbing of the originals with each other in the original separating mechanism is reduced, and the contamination of the originals due to the rubbing of the originals can be reduced.

Further, according to the present invention, the deflection plate made of an elastic member is disposed so as to face the lower end of the limiting plate and is inclined upward from the upper surface of the lower guide plate toward the downstream side. Since the uppermost original that tries to pass between the lower end of the limiting plate and the lower guide plate while overlapping is surely brought into contact with the friction surface of the limiting plate, it moves to the downstream side. Is regulated, it is possible to more reliably reduce the number of documents conveyed toward the document separating mechanism.

[Brief description of drawings]

FIG. 1 is a perspective view showing a state in which a preferred embodiment of an automatic document feeder constructed according to the present invention is installed in an electrostatic copying machine.

FIG. 2 is a schematic sectional view of the automatic document feeder shown in FIG.

FIG. 3 is an enlarged sectional view showing a carry-in unit of the automatic document feeder shown in FIGS. 1 and 2.

4 is an exploded perspective view of the carry-in means shown in FIG.

FIG. 5 is a perspective view of a front separating means installed in the carry-in means shown in FIG.

FIG. 6 is an enlarged perspective view showing a part of a limiting plate constituting the front loosening means shown in FIG.

FIG. 7 is an explanatory view for explaining the operation of a limiting plate that constitutes the front separating means shown in FIG.

FIG. 8 is a cross-sectional view showing another embodiment of the front separating means.

9 is an exploded perspective view of a transport belt mechanism and document reversing / discharging means of the automatic document transport device shown in FIGS. 1 and 2. FIG.

FIG. 10 is a block diagram showing the configuration of control means provided in the automatic document feeder shown in FIGS. 1 and 2.

11 is a flowchart showing a processing procedure of the control means shown in FIG. 10 and showing a part of a main routine.

FIG. 12 is a flowchart showing a processing procedure of the control means shown in FIG. 10 and showing a part of a main routine.

13 is a flowchart showing a processing procedure of the control means shown in FIG. 10 and showing a part of a main routine.

FIG. 14 is a flowchart showing a processing procedure of the control means shown in FIG. 10, showing a subroutine of primary paper feeding.

15 is a flowchart showing a processing procedure of the control means shown in FIG. 10, showing a subroutine of secondary paper feeding.

16 is a flowchart showing a processing procedure of the control means shown in FIG. 10, showing a subroutine of reverse sheet feeding.

[Explanation of symbols]

 2: Electrostatic copying machine 4: Automatic document feeding device 6: Electrostatic copying machine housing 8: Transparent plate 10: Document regulating member 18: Document placing means 20: Document discharging tray 22: Document table 33: Document loading device 38 : Forward feed means 40: forward feed roller 44: forward feed pressurizing means 48: first pressurizing plate 49: second pressurizing plate 59: pre-sorting means 60: original separating mechanism 64: paper feeding roller 66: separating belt mechanism 67: drive roller 68: driven roller 69: separation belt 78: drive means 84: document stopper 87: stopper drive means 98: document feed-in path 100: transport belt mechanism 102: drive roller 104: driven roller 106: endless belt 108: document Conveyance path 114: Pair of registration rollers 116: Driving roller 118: Followed roller 120: Driving means 128: Document reversing / discharging means 130 First original feeding path 134: Reversing rollers 135a, 135b, 135c: Driven roller 140: Second original feeding path 142: Inversion path 144: Branch control plate 148: Driving roller 150: Followed roller 152: Ejection roller pair 162: Driving means 200: Control means 210: Control means for electrostatic copying machine 2 220: Operating means 230: Display means 590: Restriction plate 591: Limit plate 592: Substrate 593: High friction sheet 594: Friction surface 595: Double-sided adhesive tape 597 : Deflection plates M1, M2, M3: Electric motors FG1, FG2, FG3: Rotation amount detecting means SL1: Solenoid SL1: Latch type solenoid SL3: Solenoid CL1: Electromagnetic clutch SW1, SW2, SW3: Safety switch SW4: Original set switch SW5 : Stopper position detection means SW6, SW7, S W8: Reflective optical original detector

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Wada 1-2-2 Tamatsukuri, Chuo-ku, Osaka Mita Industrial Co., Ltd. (72) Masayuki Tsunoda 1-2-2 Tamatsukuri, Chuo-ku, Osaka Mita Within Kogyo Co., Ltd.

Claims (3)

[Claims] 1. A manuscript table on which a manuscript is placed, an upper guide plate and a lower guide plate which are vertically spaced apart from each other on the downstream side of the manuscript table, and placed on the manuscript table. A forward feed unit having a forward feed roller for feeding the original document along the upper guide plate and the lower guide plate, and regulating the original document provided downstream of the forward feed unit and fed by the forward feed unit. In an automatic document feeder including a front separating means and a document separating mechanism arranged on the downstream side of the front separating means, the front separating means is provided above the lower guide plate. Is provided with a limiting plate made of an elastic member protruding downward from the lower surface of the upper guide plate and provided at a predetermined distance from the lower guide plate, and the upstream surface of the limiting plate has a high friction coefficient. Automatic, characterized by being formed by a friction surface Manuscript conveying device. 2. The friction coefficient of the friction surface of the limiting plate is determined by the frictional force F1 between documents placed on the document table, the frictional force F2 between the limiting plate and the document leading end surface, and the document table. The automatic document feeder according to claim 1, wherein a relationship between a document placed on the document and a frictional force F3 between the forward feed roller is set to satisfy F1 <F2 <F3. 3. A deflection plate, which is disposed so as to face the lower end of the limiting plate and is made of an elastic member, is provided so as to be inclined upward from the upper surface of the lower guide plate toward the downstream side, The automatic document feeder according to claim 1.