JPH1020572A - Air-feeding type recirculating document feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air-feeding type recirculating document feeder by which a document is easily taken out from a document placing plate and the matching of the documents on the ducument placing plate is always excellently maintained. SOLUTION: The documents placed on the placing plate 210 are pushed out to a document set position by a moving unit 300 and set. By making air blow toward the leading edge part of the set document from a ventilation port 552, the document of a lowermost stage is separated from the other documents, attracted to a pulling-in belt 571 at the same time and sent out. The document whose image is read is returned to the plate 210. When the feeding action of the document is finished, the unit 300 is retreated to a prescribed position. Besides, the belt 571 is reversely made to travel in a prescribed time. Therefore, the document is returned to the plate 210 so that the document of the lowermost stage is moved to an upstream side in a feeding direction by being attracted by the belt 571 and the documents of an upper side are moved to the upstream side in the feeding direction by the air from the port 552. Thus, since a gap is formed between the leading edge part of the document and the easing of a document supply part 400, the document is easily taken out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus, such as a copying machine, which sends an original to be read by an image reading apparatus from an original placing plate by using an air suction force to read an image. The present invention relates to an air-feed type circulating document feeder in which a document after being received is received by a document placing plate.

[0002]

2. Description of the Related Art For example, a document feeder mounted on a copying machine and automatically supplying a document to be copied onto a contact glass of the copying machine is known. In a conventional document feeder, a document placed on a document placing plate is sent out using air suction force, and after an image is read by a copying machine, the document is returned to the document placing plate. There is an air-feed type circulating document feeder (Japanese Patent Laid-Open No. 1-1394).
No. 40).

In the device disclosed in the above publication,
The lowest document among the documents set on the document placing plate is attracted to the pull-in belt by air, and air is blown to the leading edge of the document, so that the lowest document is separated from the upper document. Then, the lowermost document is sequentially supplied. The supplied original is placed on the contact glass (platen glass) of the copier, and after the image is read, the original is placed on the original placing plate (when the original before reading remains on the original placing plate). , On the original).

[0004]

However, in the above-mentioned prior art, the original placing plate is inclined to make it easier to take out the original from the original placing plate. The inclination is set such that the downstream side is higher than the upstream side in the document conveyance direction. Therefore, the document on the document placing plate, particularly, the returned document may slip and vary due to the inclination.

Therefore, an object of the present invention is to solve the above-mentioned technical problem, to easily take out a document from a document placing plate,
Further, an object of the present invention is to provide an air-feed type circulating document feeder capable of always maintaining good alignment of a document on a document placing plate.

[0006]

According to a first aspect of the present invention, there is provided an air-feed type circulating document feeder, comprising: a document placing plate on which a document is placed; Air blowing means for separating the lowermost original from other originals by blowing air to the leading end of the original set at the first predetermined position; and the lowermost part of the original set at the first predetermined position. A draw-in belt for sending out the original from the original placing plate, and air suction means for adsorbing the lowermost original to the draw-in belt by an air suction force. When the document is conveyed, the document is conveyed from the home position along the document placement plate at the start of document conveyance, and the document is conveyed. In the direction A moving unit that pushes the moving unit to the first predetermined position, an operation end detecting unit that detects that the document conveying operation has ended, and a moving unit that is moved to the first predetermined position after the operation conveying unit detects that the document conveying operation has ended. Unit movement control means for retreating to a second predetermined position between the position and the home position, and a retracting belt when the moving unit is retreated from the first predetermined position to the second predetermined position by the unit movement control means. And belt running control means for running in reverse.

According to the first aspect of the invention, when the operation completion detecting means detects that the document conveying operation has been completed, the unit movement control means moves the moving unit back to the second predetermined position, and The pull-in belt is run backward by the belt running means. As a result, the original returned to the original placing plate is moved from the first predetermined position to the moving unit by the pull-in belt. Therefore,
A gap is formed on the leading end side of the document, and the leading edge of the document is easily grasped, so that the document can be easily removed from the document placing plate.

The invention according to claim 2 further comprises means for driving the air blowing means and the air suction means while the retracting belt is running backward by the belt running control means. 1 is an air feed type circulating document feeder. According to the second aspect of the present invention, when the draw-in belt moves backward and the document is moved to the moving unit, the air blowing means and the air suction means are driven, and the lowermost document is the air suction means. As a result, the document above the lowermost document is pressed against the moving unit by the air blown by the air blowing means. Therefore, when the original moves, the original does not vary.

The invention according to claim 3 further includes document presence detecting means for detecting the presence or absence of a document on the document placing plate, wherein the unit movement control means returns the moving unit to the second predetermined position. After that, when it is determined by referring to the output of the document presence detecting means that the document does not exist on the document placing plate, retreat control means for retreating the moving unit to the home position is provided. An air-feed type circulating document feeder according to claim 1 or 2.

According to the third aspect of the present invention, when the user removes the original on the original placing plate and detects that the original on the original placing plate is gone by the original presence detecting means. The mobile unit is returned to the home position under the control of the reverse control means. That is, the moving unit is not returned to the home position until the original document which has been easily taken out by the configuration of claim 1 is removed from the original placing plate. Therefore, for example, even if the document placing plate is inclined so that the rear end side of the document is lowered, the returned unit is prevented from sliding along the inclination by the moving unit, and the document is separated. Nothing.

According to a fourth aspect of the present invention, there is provided the document placing plate,
4. The air feeder according to claim 1, wherein a pair of width regulating plates are provided so as to face each other for positioning the original in a direction orthogonal to the original transport direction. This is a recirculating document feeder.
According to the configuration of the fourth aspect, the document existing on the document placing plate is positioned in the document transport direction by the moving unit, and is positioned in the direction orthogonal to the document transport direction by the pair of width regulating plates. . Thus, the document existing on the document placing plate is not separated by the air blown to the leading end of the document.

[0012]

An embodiment of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a sectional view showing an internal configuration of an air-feed type circulating document feeder according to an embodiment of the present invention. Referring to FIG. 1, an air-feed type circulating document feeder (hereinafter referred to as "RD
H ". ) 100 is mounted on the upper surface of the copying machine main body 50 and automatically supplies the original to the contact glass 51 provided on the upper surface of the copying machine main body 50. Also, the original that has been once supplied onto the contact glass 51 of the copying machine body 50 and returned to the original position can be automatically supplied again. That is, the document can be circulated and supplied.

The RDH 100 is rotatably attached to the copying machine main body 50, and can be displaced between a state of covering the upper surface of the copying machine main body 50 (a state shown in FIG. 1) and a state of opening. I have. The RDH 100 includes a document placement unit 200 for placing a document, a moving unit 300 for positioning and setting the placed document, and a document for supplying the set document to the copier main body 50. A feeding unit 400, a document separation mechanism 500 for separating the set documents in order to feed the documents one by one to the document feeding unit 400, and a document supplied to the copying machine main body 50 in the feeding direction or the reverse direction. The apparatus includes a transport belt unit 600 for moving in the supply direction, and a document discharge unit 700 for discharging a document from the copying machine main body 50 side.

Next, the function of each part of the RDH 100 will be described generally. First, an original is placed on the placing plate 210 of the original placing section 200. The RDH 100 according to the present embodiment is capable of setting an original of B5 size to A3 size. Then, the positioning plate 250 arranged opposite to the reference plate 230 is moved (moved in the direction perpendicular to the paper surface in the figure) according to the size of the document. As a result, the document of each size can be positioned between the reference plate 230 and the positioning plate 250 in the direction perpendicular to the plane of the drawing (the width direction of the document).
The mounting plate 210 is inclined so that the downstream side is higher than the upstream side in the document conveyance direction in order to enhance the document separation effect by air described later. Further, at a predetermined position below the mounting plate 210, the mounting plate 210
A document presence / absence sensor 295 for detecting the presence / absence of a document placed thereon is arranged.

When the copy start key provided on the copying machine main body 50 is pressed while the original is positioned in the width direction, a unit motor M1 (see FIG. 3) described later is driven, and the moving unit 300 is moved. In the direction of arrow P1. Thus, the original can be positioned in the left-right direction in the figure. Further, the moving unit 300 is provided with a document pressing mechanism 310, and the pressing bar 311 is once turned up in the direction of the arrow P3 and then falls down, thereby pressing the rear end of the document. The document pressing mechanism 310 is provided with a document height sensor 312 in association with the pressing bar 311, and the document height sensor 312 detects the position of the pressing bar 311.
As described above, the setting of the original is completed with the original positioned in two directions.

The original set on the original placing section 200 is
The sheet is guided to a document supply unit 400, is fed along a sheet feeding path 402 by a sheet feeding roller pair 401, and is conveyed by a conveyor belt unit 600 to a contact glass 51 of the copying machine main body 50.
It is arranged at a predetermined position above. Note that reference numeral 403 is
3 illustrates a pair of registration rollers. Registration roller pair 40
Reference numeral 3 is for adjusting the timing at which the document sent along the paper feed path 402 is temporarily stopped in the paper feed path 402 and fed onto the contact glass 51.

Reference numeral 404 denotes a pair of reversing rollers. The reversing roller pair 404 is for reversing the duplex document after copying. The double-sided document on the contact glass 51 on which copying on one side has been completed is returned to the reversing path 405 by the transport belt unit 600. The pulled back double-sided document is reversed by passing through the reversing path 405 with the rotation of the conveyor belt unit 600, the pair of reversing rollers 404, and the registration roller 403,
Contact glass 5 by conveyor belt unit 600
1 again.

The document separation mechanism 500 separates a document using air before the document is guided to the document supply unit 400. The lowermost document among the documents placed on the mounting plate 210 is sucked by the air suction unit 510 to the pull-in belt 571 by the air, and the document above the sucked document is a document. The air is levitated by air by the action of the levitating section 550. The document attracted to the pull-in belt 571 is drawn into the document supply unit 400 by the function of the document pull-in unit 570.

The original placed on the contact glass 51 by the transport belt unit 600 is sent to the original discharge unit 700 by the transport belt unit 600 after a predetermined copying operation is performed by the copying machine main body 50. The transport belt unit 600 is arranged to face the contact glass 51 in the state shown in the figure, and is driven by a motor (not shown). When reversing the original, the original is sent to the reversing roller pair 404 by rotating the transport belt unit 600 in the reverse direction.

The document sent to the document discharge unit 700 is drawn into a paper discharge path 702 by a pair of paper discharge rollers 701. Thereafter, the original is sent along a paper discharge path 702 by a paper discharge roller pair 703, and the paper discharge roller pair 704, 705
To return to the original placing section 200.
The moving unit 300 moves forward and backward with respect to the document discharge unit 700, and a part of the paper discharge path 702 (downstream in the paper discharge direction) is connected between the document discharge unit 700 and the movable unit 300. It is constituted by a gap formed between them. Further, since the moving unit 300 advances and retreats with respect to the document discharge unit 700, the discharge roller pair 705 is
The moving unit 300 is provided on the side of the moving unit 300 and moves with the movement of the moving unit 300. Further, the document discharge unit 700 is provided with a home position sensor 302 for detecting that the moving unit 300 is located at a home position indicated by a solid line.

Next, the operation performed during document setting and the detailed configuration of the document separating mechanism 500 will be described with reference to FIGS. Referring to FIGS. 1 and 2, reference plate 230 and positioning plate 25
0 are arranged opposite to each other, and the original
It is arranged along the reference plate 230 fixed to 10. Positioning plate 2 according to the size of the placed document
The document is positioned in the width direction by sliding 50 along rail 251 in a direction P4 orthogonal to the document transport direction. A document size sensor (not shown) is provided below the placing plate 210 in relation to the positioning plate 250, and the document size sensor detects the document size based on the position of the positioning plate 250.

When the copy start key provided in the copying machine main body 50 is pressed in the state where the document is positioned in the width direction in this manner, the document pressing mechanism 310 provided in the moving unit 300 is moved. When the document is driven, the rear end of the document is pressed by the pressing bar 311. Then, the unit motor M1 is driven, and the moving unit 300 waiting at the home position (the position indicated by the solid line in FIG. 1) moves in the P1 direction by a distance corresponding to the document size detected by the document size sensor. (To the position shown by the two-dot chain line in FIG. 1). More specifically, the unit motor M1 is constituted by, for example, a stepping motor, and the unit motor M1 is rotationally driven by the number of steps corresponding to the document size, and is moved to the position indicated by the two-dot chain line.

By the movement of the mobile unit 300,
The original is pushed out to the position of the original D shown by a two-dot chain line in FIG. As a result, the original D has
0 is restricted by the front plate 301,
It is set in a state where it is regulated by the positioning plate 30 and the positioning plate 250. Therefore, the document does not vary due to the air blown out from an air outlet 552 described later or the inclination of the mounting plate 210.

Referring to FIGS. 1 and 3, mounting plate 210
In the direction perpendicular to the document conveying direction,
Six pull-in belts 572 to 577 are arranged in parallel as 71, and four pull-in belts 572 to 57
5 is wound around rollers 513 and 514. The remaining two pull-in belts 576 and 577 are wound around a roller 513 and a roller (not shown). Roller 513
Is a drive roller to which the rotational force of the belt motor M2 is transmitted. Further, a plurality of through holes 578 are formed in the pull-in belts 572 to 577. The six draw-in belts 572 to 577 and the rollers 513 and 514 constitute a document draw-in section 570.

Between the rollers 513 and 514,
A suction duct 511 is provided. Suction duct 511
, A plurality of suction ports 512 are formed on a surface facing the four pull-in belts 572 to 575.
In addition, a suction fan 515 is connected to the suction duct 511, and four suction belts 572 to 575 are provided by the operation of the suction fan 515 as indicated by white arrows.
Air is sucked in through the through hole 578 and the suction port 512. The suction fan 515 includes a suction fan motor M3.
It is adapted to be driven by. The document suction unit 51 is formed by the suction duct 511 and the suction fan 515.
0 is configured.

The blower fan 5 is located adjacent to the suction fan 515.
53 is provided, and the blower fan 553 is driven by a blower fan motor M4. The blower duct 551 is connected to the blower fan 553.
The air duct 551 is disposed downstream of the mounting plate 210 in the document transport direction. In the air duct 551,
A plurality of air outlets 552 are formed at predetermined intervals from each other in a direction orthogonal to the document transport direction. Blow port 55
Reference numeral 2 indicates that the air sent from the blower fan 553 is blown toward the leading end of the document D sucked to the pull-in belts 572 to 575, as indicated by the black arrow. The document duct 551 and the fan 553 constitute a document floating unit 550.

Therefore, when the document is started to be conveyed and air is sucked in from the suction port 512, the lowermost document is sucked into the through holes 578 and is pulled in by the pull-in belts 572-5.
75. On the other hand, the document above the lowermost document is levitated by the air blown out from the air blowing port 552. Therefore, the lowermost document is reliably separated from other documents. In this state, the roller 513 is driven by the belt motor M2 and the pull-in belts 572-5
As the document 75 travels, only the lowermost document is sent to the document supply unit 400 side.

FIG. 4 is a diagram showing various operation states of the RDH 100. In a state where the original is not placed on the placing plate 210 of the original setting section 200, as shown in FIG. 4A, the moving unit 300 is waiting at the home position. The document pressing mechanism 310 is completely stored inside the moving unit 300. Therefore, the pressing bar 311 does not interfere when the document is set.

After the original is placed on the mounting plate 210 and the positioning plate 250 is moved to match the width of the original, and the copy start key of the copier main body 50 is pressed, the moving unit 300 is moved as described above. Is moved in the direction of arrow P1. Accordingly, the pull-in belt 571 starts running. Further, the holding bar 311 is moved in the direction of arrow P5, and the tip of the holding bar 311 is moved to the moving unit 300.
And the rear end of the document is pressed down (see FIG. 4).
(B)). This allows the air outlet 552 to separate the lowermost document from the document above the lowermost document.
There is no possibility that the original on the upper side is separated by the air blown out from the upper side. Further, the air from the air outlet 552 is less likely to leak from the rear end of the document, and the floating state of the front end of the document is improved. Note that the original is pressed by the pressing bar 311 to such an extent that it does not vary, and does not affect the loading into the original supply unit 400.

Further, by detecting the position of the pressing bar 311 at this time by the document height sensor 312, the amount of the set document can be known. When the content is read for copying, the original is returned to the top of the set original, specifically, onto the holding bar 311. Therefore, the original before reading and the original that has already been read are separated by the pressing bar 311. The original returned to the mounting plate 210 is not pressed by the pressing bar 311, but the reference plate 230
Since both ends are regulated by the positioning plate 250 and the rear end is regulated by the moving unit 300,
It is not disturbed by the air from the air outlet 552.

When reading of all set originals is completed, the state shown in FIG. 4C is obtained. The mounting plate 210 is formed with a concave portion 211 which is one step lower than the upper surface of the mounting plate 210, and
Fits into the recess 211. The position of the pressing bar 311 at this time is detected by the document height sensor 312, and it is detected that there is no document whose content has never been read.

When a plurality of copies are required, FIG.
In the state shown in FIG.
After being moved in six directions, the holding bar 311 is temporarily stored in the moving unit 300. Then, press bar 311
Comes out of the moving unit 300 again, comes to the state shown in FIG. 4B, and the above-described transport operation is repeated. When the required number of copies are made and the state shown in FIG. 4C is reached, the holding bar 311 is moved in the direction of arrow P6 and stored in the moving unit 300. Then, the moving unit 300 is moved to a predetermined position in the direction of the arrow P7.
At this time, the pull-in belt 571 runs backward, the lowermost document is sucked to the pull-in belt 571, and the upper document is moved in the direction opposite to the transport direction by the air blown out from the air blowing port 552. To the mobile unit 300. As a result, a gap is generated between the leading end portion of the document and the casing covering the document supply unit 400,
The state shown in FIG.

When the original is removed from the mounting plate 210, the moving unit 300 is moved from the predetermined position in the direction of arrow P7 and returned to the home position.
The state shown in FIG. One of the features of the present invention is that when the required number of copies are made and the document transport operation is completed, the moving unit 300 is returned to a predetermined position, and the pull-in belt 571 is moved backward to move the document. Moving while being pressed against the moving unit 300.

FIG. 5 is a block diagram showing the configuration of the control circuit of the RDH 100, and also shows the relationship with the control unit of the copier main body 50. This control circuit uses R as a control center.
A DH CPU 101 is provided. This RDH CPU
101 includes a document presence sensor 295 and a document height sensor 3
12 and an output from the home position sensor 302. The RDH CPU 101 is connected to a copier CPU 52 provided in the copier body 50.

The copying machine CPU 52 is supplied with a signal from an operation unit 55 having a copy start key 53 for instructing the start of a copying operation, a numeric keypad 54 and the like. Numeric keys 54 are used, for example, to input how many copies of one set of originals are required. The copying machine CPU 52 starts controlling the copying operation of the copying machine body 50 based on a signal from the copy start key 53. Further, the copying machine CPU 52 gives an instruction necessary for driving the RDH 100 to the RDH CPU 101.

The RDH CPU 101 has a unit motor M1 for moving the moving unit 300 and a pull-in belt 57 in addition to the sensor and the copying machine CPU 52.
, A belt motor M2 for running the vehicle 1 and a suction fan 5
The suction fan motor M3 for driving the fan 15 and the blower fan motor M4 for driving the blower fan 553 are connected. The RDH CPU 101 controls the driving of each of the motors based on signals from the above-described sensors, control commands from the copier CPU 52, and the like.

FIG. 6 is a flowchart mainly showing the movement control operation of the mobile unit 300. Hereinafter, the movement control of the moving unit 630 will be described according to the flow of FIG. 6 with reference to FIGS. 4 and 5. First, after the user places a document on the placing plate 210 and moves the positioning plate 250 according to the size of the document,
The ten keys 54 of the operation unit 55 of the copier main body 50 are operated to set how many copies of the document are required. When the copy start key 53 is pressed, the document pressing mechanism 310 is driven to drive the rear end of the document. Is pressed by the pressing bar 311 (step S1), and the pressing bar 311 at this time is pressed.
Is detected by the document height sensor 312 based on the position of the document.

Thereafter, the unit motor M1 is normally rotated for a predetermined time (a predetermined number of steps) according to the size of the document detected by the document size sensor. As a result, FIG.
As shown in (a), the moving unit 300 moves in the direction P1, and the document is pushed out to the document setting position (step S2). Further, the count value of the internal counter of the RDH CPU 101 is set to 1 (step S3).

Further, with the movement of the moving unit 300, the suction fan motor M3 and the blower fan motor M4 are driven so that the air flow amount matches the amount of the document detected by the document height sensor 312, and the belt The pull-in belt 571 is driven by driving the motor M2.
As a result, as shown in FIG. 4B, the originals set at the original set position are taken into the original supply unit 400 one by one starting from the lowest original (step S).
4).

When the originals set at the original set position are sequentially conveyed and the last original (the uppermost original at the start of the original conveyance) is taken in from the mounting table 210, as shown in FIG. The tip of the holding bar 311 contacts the mounting plate 210. Pressing bar 311 at this time
Is detected by the document height sensor 312,
It is input to the CPU 101. The CPU 101 determines that the final document has been captured from the placing plate 210 based on a signal from the document height sensor 312 (step S5).

If the determination in step S5 is affirmative, the process proceeds to step S6, where it is determined whether the set number of copies has been created. Specifically, it is determined whether the set number of copies is equal to the count value of the counter (step S6). For example, assuming that two copies of the document are required, since only one copy has been made at this time, the determination in step S6 is denied.
If the original needs to be transported again,
After the holding bar 311 that has come into contact with 0 is temporarily stored in the moving unit 300 (step S15), the holding bar 311 is again projected from the moving unit 300, and the document on the mounting plate 210 is pressed again by the holding bar 311 (step S1).
6). At this point, the second round of conveyance is started, and 1 is added to the count value, and the count value is set to 2.

When the conveyance of the original is continued and the last original of the second round is taken in, the pressing bar 311 is moved to the placing plate 21.
0 again, and the determination in step S5 is affirmed. Then, in step S6, the value of the counter is checked. Under the above assumption, the required number of copies is two, so
The determination in step S6 is affirmed, and the routine goes to step S7.

In step S7, it is determined whether or not a predetermined time has elapsed since the last document of the second cycle has been fetched. The predetermined time period means that after the document is taken in from the mounting table 210,
Is set to the time before returning to. Step S7
Is affirmative, it is determined that there is no document on the transport path of the RDH 100, the belt motor M2 is stopped, and the running of the pull-in belt 571 is stopped (step S8). Then, the holding bar 311 moves the moving unit 30.
0 (step S9), the unit motor M1
Is reversed for a predetermined time (a predetermined number of steps), and the mobile unit 300 moves backward to a predetermined position (step S1).
0). Further, with the retreat of the moving unit 300, the belt motor M2 is also reversely rotated for a predetermined time, and
Is reversed (step S11). At this time, the suction fan 515 and the blower fan 553 are also driven, and the original that has been returned to the original set position is moved to the upstream side in the original transport direction while the lowermost original is sucked by the pull-in belt 571. The upper document is moved to the upstream side in the document transport direction by the air blown out from the blowing port 552 and pressed against the moving unit 300 (FIG. 4).
(D)).

As a result, a sufficient space is provided between the leading end portion of the document and the casing covering the document supply unit 400 to allow the user to put his / her hand, and the document is removed from the placing plate 210. It will be easier. The original is placed on the mounting plate 21.
Instead of slipping due to the inclination of 0, the lowermost document moves while being sucked by the pull-in belt 571, and the upper document is moved by air, so that the document does not vary.

When the moving unit 300 is returned to the predetermined position in this way, the suction fan motor M3 and the blower fan motor M4 are turned off, and the suction fan 515 is turned off.
And the blower fan 553 is stopped (step S1).
2). Then, it is determined whether or not the returned document exists on the placing plate 210 (step S13). This determination is made based on the output of the document presence sensor 295.

When the user removes the original from the mounting plate 210, the determination in step S13 is negative. Then, the unit motor M1 is reversed again, and the moving unit 300 moves in the P7 direction shown in FIG. When the home position sensor 302 detects that the mobile unit 300 has returned to the home position, the unit motor M1 is stopped (Step S).
14).

As described above, after the necessary number of copies have been made, when the final document is returned to the placing plate 210 and the transport operation is completed, the moving unit 300 is returned to the predetermined position. The moving unit 300 is returned to the home position after the user or the like removes the document that has been easily taken out from the mounting plate 210 by the user or the like. Therefore, the rear end of the returned document is always regulated by the moving unit 300, and the document does not vary due to the inclination of the mounting plate 210.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. For example, in the above-described embodiment, the unit motor M1 is stopped in response to the detection of the return of the mobile unit 300 to the home position by the home position sensor 302. The mobile unit 300 may return to the home position by reversing the number of steps.

When a predetermined time has elapsed since the conveyance of the final document has started, the final document is placed on the placing plate 210.
However, even if a discharge detection sensor that is turned on / off as the paper passes is provided near the discharge roller pair 605, and the discharge detection sensor detects that the discharge has been completed, Good. In addition, various changes can be made within the scope described in the claims.

[0050]

According to the first aspect of the present invention, when the moving unit is retracted to the second predetermined position and the retracting belt is moved backward, the original returned to the original placing plate is not moved. Is moved from the first predetermined position to the moving unit side by the retracting belt. Therefore, a gap is formed on the leading end side of the document, and the leading edge of the document is easily grasped, so that the document can be easily removed from the document placing plate.

According to the second aspect of the present invention, when the pull-in belt runs backward, the air blowing means and the air suction means are driven, and the lowermost document is sucked by the pull-in belt by the air suction means. The document above the lowermost document is pressed against the moving unit by the air blown by the air blowing means. Therefore,
When the original moves, the original does not vary.

According to the third aspect of the present invention, until the original document which has been easily taken out is removed from the original placing plate,
Mobile units are not returned to their home position. Therefore, for example, even if the document placing plate is inclined so that the rear end side of the document is lowered, the returned document is prevented from sliding along the inclination by the moving unit.
Manuscripts are not scattered.

According to the fourth aspect of the present invention, the original on the original placing plate is regulated in the transport direction and the direction orthogonal to the transport direction. Absent.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an internal configuration of an air-feed type circulating document feeder according to an embodiment of the present invention.

FIG. 2 is a plan view showing a configuration of the document separation mechanism with a part cut away, and shows a state in which a conveyance operation has not been started;

FIG. 3 is a plan view showing a configuration of the document separating mechanism with a part cut away, showing a state where a document is set.

FIG. 4 is a diagram showing an operation state of the RDH.

FIG. 5 is a block diagram illustrating a configuration of the RDH control circuit.

FIG. 6 is a flowchart illustrating a drive control operation of the moving unit.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 Air feed type recirculating document feeder (RDH) 101 CPU for RDH 210 Mounting plate 230 Reference plate 250 Positioning plate 300 Moving unit 295 Document presence sensor 312 Document height sensor M1 Unit motor M2 Belt motor M3 Suction fan motor M4 Ventilation Fan motor

Claims (4)

[Claims] A lowermost original is blown by blowing air to an original placing plate on which an original is placed and a leading end portion of the original set at a first predetermined position on the original placing plate. Air blowing means for separating the original from the original, a retracting belt for sending out the lowermost original of the originals set at the first predetermined position from the original placing plate, and adsorbing the lowermost original to the intake belt by an air suction force. An air suction means for causing the original to be sent out from the original placing plate and conveyed along the conveying path to return to the first predetermined position. A moving unit for moving the original from the home position along the original placing plate to push the original to a first predetermined position in the original conveying direction at the start of the original conveyance, and an operation end detecting means for detecting that the original conveying operation has been completed; And unit movement control means for retreating the moving unit to a second predetermined position between the first predetermined position and the home position after detecting that the document conveyance operation has been completed by the operation end detection means; A belt travel control means for reversing the pull-in belt when the moving unit is retracted from the first predetermined position to the second predetermined position by the unit movement control means. Transport device. 2. The air-feed type circulation type according to claim 1, further comprising a means for driving said air blowing means and said air suction means while said pull-in belt is running backward by said belt running control means. Document feeder. 3. The apparatus according to claim 1, further comprising a document presence detecting means for detecting the presence or absence of the document on the document placing plate, wherein the unit movement control means detects the presence or absence of the document after the moving unit is returned to the second predetermined position. 2. A retraction control means for retreating a moving unit to a home position when it is determined by referring to an output of the means that there is no document on the document placing plate. Item 3. An air-feed circulation type document feeder according to Item 2. 4. A pair of width regulating plates are provided on the original placing plate so as to face each other in order to position the original in a direction orthogonal to the original conveying direction. 4. An air-feed type circulating document feeder according to claim 3.