JPH08655B2 - Automatic document feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an automatic document feeder for automatically feeding a document to an image processing apparatus such as a copying machine, an image reader, a laser printer, a liquid crystal printer, an ion printer, and a printing machine. Regarding the device.

[Conventional technology]

2. Description of the Related Art Conventionally, as an image forming apparatus, for example, an apparatus that automatically feeds originals one by one onto a platen glass (platen) of a copying machine and discharges the sheets after copying is known in which an original tray and a discharge tray are arranged on both sides of the platen. . There is also one in which a document tray and a paper discharge tray are arranged side by side on only one of the platens.

[Problems to be Solved by the Invention]

However, in the case where the document tray discharge trays are arranged so as to face each other on both sides of the platen, an extra space is required on both sides of the platen, resulting in an increase in size of the apparatus. On the other hand, one of the platens has a document tray and a discharge tray. In the side-by-side arrangement, the originals are fed and discharged by the forward and reverse rotations of the transporting means, but the curl or tip of the leading edge of the originals is likely to occur at the branch points of these passages, and JAM or jamming is likely to occur. Had.

[Object of the Invention]

It is an object of the present invention to provide a device that can reduce the size of an automatic document feeder and that causes less jamming or jamming of a document at a document transport path, particularly at a branch point of the path.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

In this embodiment, as shown in FIGS. 1 and 2, the document feeding device 5 is described as an example on the platen glass 3 of the copying machine 1 which is an image forming apparatus. A stopper 4 serving as a reference position for a copy document is provided at one end of the copying machine 1.

The automatic document feeder 5 includes a document tray 7, a feeding separation unit 9, a paper feed path 11, a transport path switching unit 13, a transport path switching drive unit 15, a belt transport unit 17, a paper discharge path (reversal path) 19, and a paper discharge path. The tray 21 and the like are provided so that the original P can be automatically fed and ejected, and the other parts except the transport path switching unit 13 are integrated with the cover C and can be opened and closed via a hinge on the back surface of the copying machine 1. It is attached to and can be operated manually.

The feeding separating section 9 is configured as shown in FIGS. 3 and 4.

Roller holes 27 are provided in the guides 23 and 25 forming the paper feed path 11,
29 is provided, and a separating unit such as a separating roller 31 and a sheet feeding unit such as a sheet feeding roller 33 are arranged to face each other. The separating means and the paper feeding means may be belts or the like. By the way, the separating means and the paper feeding means constitute a feeding means.

The separation roller 31 is attached to the rotating shaft 35 via a one-way clutch, and is driven to rotate in the direction opposite to the paper feeding direction (clockwise in the figure), and the feeding roller 33 is also attached to the rotating shaft 37 via a one-way clutch. Paper feed direction (clockwise in the figure)
Is driven to rotate.

An arm 43 having a connecting portion 39 and a locking portion 41 is rotatably attached to the shaft 37 of the paper feeding roller 33. Connection
A pickup roller 47, which is a feeding means, is attached to 39 through a rotation shaft 45, and is rotated together with the paper feed roller 33 through timing pulleys 44 and 46 and a timing belt 49. In addition, the middle of the belt 49 is the roller 51.
To support a large space under the arm 43. That is, a space is provided so that the document fed by the pickup roller 47 and abutted against the pressure contact portion between the separation roller 31 and the paper feed roller 33 is easily bent.

In the vicinity of the pickup roller 47, as shown in FIG. 2, a lever type or optical type sensor S ₁ for detecting that the document P is set on the document tray 7 is attached.

A lever 55 attached to a shaft 53 driven by a solenoid 52 is provided above the arm 43. The lever 55 supports the locking portion 41 and locks the rotation of the arm 43. The spring 55 is used to return the lever 55.
It is done in. The solenoid 52, shaft 53, lever 55,
The engaging portion 41, the spring 56, and the like constitute the contacting / separating means.

Further, below the guide 23, a set stopper 59 attached to the shaft 57 is provided so that the document P can be fed through the paper feed path except during separation.
I try not to break into 11.

A sensor S ₂ for detecting the document P is provided in front of the paper feed roller 33 as shown in FIG.

As shown in FIG. 1, the transport path switching unit 13 serving as a transport path switching unit includes a paper feed path 11 (first transport path) and a paper discharge path.
A switching flapper 61 and an arm 63 for assisting the driving of the switching flapper 61 are provided at a branch portion with respect to 19 (second transport path).

The switching flapper 61 is rotatable around a shaft 65 and is urged downward by a spring 67. Switching flapper 61
Is formed of a metal material such as aluminum or iron, a synthetic resin such as plastic, or an elastic body such as a synthetic resin film or sheet, and the shape and mounting method may be other.

The arm 63 is rotatable around a shaft 69, one end of which receives the driving force from the transport path switching drive unit 15 and the other end of which pushes up the switching flapper 61.

In the transport path switching drive unit 15, for example, a solenoid 75, a return spring 77, and a slide arm 79 are attached to an arm 73 that is movable around a shaft 71, and the iron of the solenoid 75 is attracted by the excitation of the solenoid 75, and the arm 73 is moved. Is rotated downward, the slide arm 79 is lowered, and the arm 63 of the transport path switching unit 13 is pushed. Return spring 77
It is done in.

By the way, since the transport path switching unit is separated into the transport path switching unit 13 and the transport path switching driving unit 15, the mechanism (the transport path switching unit 13) provided in the platen glass 3 of the copying machine 1 on the left and right portions where the mounting space is small. It needs less.

Further, since the transport path switching drive unit 15 that requires electrical control is provided on the cover C side, the transport path switching unit 13 does not require electrical wiring, and only the wiring inside the cover C is required. That is, the wiring is not divided and wiring is easy.

Further, even if a document hits the switching flapper 61 and JAMs, the JAM paper can be easily removed because the transport path switching unit 13 and the transport path switching drive unit are separated. The belt conveyor 17 has a conveyor belt 81 supported by rollers 83 and 85 at both ends and a roller 87 at the middle.
Supported by.

Paper discharge rollers 82, 84, 86, 88 are provided in the paper discharge path 19, and the originals guided by switching the conveyance path to the paper discharge path 19 side by the switching flapper 61 are discharged to the paper discharge tray 21. ing. The paper discharge rollers 82 and 86 obtain driving force from the drive mechanism, and the paper discharge rollers 84 and 88 follow the movement of the paper discharge rollers 82 and 86.

Note that the discharge outlet is provided with a sheet discharge sensor S ₃ for detecting the trailing end of the document as in the second figure.

The drive mechanism of the automatic document feeder configured as described above is configured as shown in FIGS.

First, as shown in FIG. 5, the rotary shaft 93 of the single motor 91 which is the driving means is connected to the rotary shaft 107 of the roller 85 via the gears 95, 96, 101, 103 and 105.

Further, the gear 95 is connected to the electromagnetic clutch 11 via the gears 109 and 111.
It is connected to three input gears 115. And electromagnetic clutch
The output gear 117 of 113 is a gear 119 attached to the rotating shaft 37.
Are in mesh with each other.

On the other hand, a timing pulley 121 is mounted coaxially with the gear 109, and the timing pulley 121 is the timing belt 1
It is connected to the aiming pulley 125 via 23.

A gear 127 is mounted coaxially with the timing pulley 125, and this gear 127 meshes with a gear 131 mounted on a rotary shaft 129. A gear 133 is attached to the rotating shaft 129 and meshes with a gear 135 which is integral with the timing pulley 44. The timing pulley 44 and the gear 135 are the rotary shaft 3
The rotating shaft 37 is not fixed with respect to 7, but is rotatable.

Further, as shown in FIG. 6, a gear 137 meshes with the gear 101. The gear 137 is attached to the rotary shaft together with the timing pulley 139 like the paper discharge roller 82. The timing pulley 139 is connected by a timing belt 141 and a timing pulley 141 attached to the rotation shaft of the paper discharge roller 86.

Further, as shown in FIG. 7, the gear 117 has a separating roller 31.
It meshes with a gear 145 attached to the rotating shaft 35 of the.

With such a configuration, the pickup roller 47, the separation roller 31, the paper feeding roller 33, which move differently,
The conveyor belt 81 and the paper discharge rollers 82 and 86 can be driven by a single motor 91. Therefore, the paper feeding and discharging can be performed only by controlling the motor 91, which makes the control very simple. It also leads to downsizing, weight reduction, and significant cost reduction.

Further, since the original tray 7 and the paper discharge tray 21 are provided on one side in a concentrated manner, it is easy to set the original P and take out the discharged original. Further, since the center of gravity of the automatic document feeder 5 is on the right side, when the cover C is opened and closed with the right hand, a force acts on the position of the center of gravity, so that the cover C can be opened and closed smoothly.

The operation of the automatic document feeder having the above structure will be described with reference to the timing chart of FIG.

First, the original P is placed on the original tray 7 with the surface of the original P facing downward.
When is set, the sensor S ₁ detects the document P, and the document P can be automatically fed.

When the paper feed button is pressed in such a state, the solenoid 52 shown in FIG. 3 is excited and the lever 55 rotates counterclockwise in the drawing to obtain the state shown in FIG. Therefore, the pickup roller 47 falls on the document P.

On the other hand, the rotation of the shaft 53 causes the shaft 57 to rotate in conjunction with each other, and the set stopper 59 rotates downward. Therefore, the gate of the document P is opened and the document can be fed. Further, the separation roller 31 is pressed against the paper feed roller 33.

When the pickup roller 47 contacts the original P on the original tray 7, the motor 91 of FIG. 5 is rotated to rotate the pickup roller 47 in the direction of the solid line arrow. Since the electromagnetic clutch 113 is not energized yet, the separation roller 31 and the paper feed roller 33 are not rotating.

The original P is sent out by the rotation of the pickup roller 47, but the leading end is regulated by the separation roller 31 and the paper feed roller 33, so the original is bent and the leading end is registered and corrected.

At this time, for example, when the originals P ₁ and P ₂ are sent out as shown in FIG. 4, the originals P ₁ and P ₂ are separated when being bent.

The electromagnetic clutch 11 is rotated within a predetermined time after the motor 91 rotates.
Turn on 3. As a result, the driving force transmitted to the gear 115 is transmitted by the gear 117, and as shown in FIG.
5 and 119 rotate, and the separation roller 31 and the paper feed roller 33 rotate as indicated by the broken line in FIG.

Therefore, while sending out the registered document P ₁ ,
Prevents document P ₂ from advancing. Then, when the sensor S ₂ is turned on, the excitation of the solenoid 52 is released, and the pickup roller 47 moves away from the original P.

In addition, the rotation of the shaft 53 causes the shaft 57 to rotate, and the set stopper
59 rises and shuts off the entrance of the paper feed path 11.

When the sent original reaches the platen glass 3,
The conveyor belt 81 conveys the platen glass 3 to the left in the drawing. Then, the document P hits the stopper 4 and
It is set to the reference position.

When the trailing edge of the document P passes the sensor S ₂ for a predetermined time, the motor 91 is stopped. This also stops the rotation of the conveyor belt 81.

Copying is performed in this state, and when the copying is completed, the motor 91 is rotated in the reverse direction and the solenoid 75 is excited.

By the reverse rotation of the motor 91, the conveyor belt 81 moves on the platen glass 3 to the right in the figure.

Further, the excitation of the solenoid 75 lowers the slide arm 79 and pushes down one end of the arm 63. Therefore, the other end rises and pushes up the switching flapper 61. Therefore, the document conveyed to the right by the conveyor belt 81 will not be changed by the switching flapper 61.
And is sent to the paper discharge path 19.

The reverse rotation of the motor 91 causes the gear 137 and the timing pulley 141 in FIG. 6 to rotate in the direction of the broken line arrow, and the paper discharge rollers 82 and 86 also rotate in the same direction to reverse the document to the paper discharge tray 21 and discharge it. . When the trailing edge of the document passes the sensor S ₃ , the solenoid 52 is excited and the next document is fed out.
Repeat the operation so far. Then, all the original P is sent out, the sensor S ₁ is turned off, and the trailing edge of the last original is detected by the sensor.
When detected in S ₃ , the document feeding operation ends.

When the originals are manually set one by one on the platen glass 3, the cover C is opened centering on the hinge, the originals are placed on the platen glass 3, and the stopper 4 is used.
Press the document against and set it at the reference position. Then, the cover C is closed again and the copy button is pressed to make a copy.

〔The invention's effect〕

According to the invention described above, a document tray on which a document is set, a feeding unit that feeds the document set on the document tray by forward rotation, and the feeding unit contacts the document only when the document is fed. A contact / separation unit, a first transport path for guiding the document delivered by the delivery unit to the platen of the image forming apparatus, and a document that is pressed against the platen and is forwardly guided from the first transport route. Forward and reverse conveying means for conveying a document to the original setting position on the platen and discharging the original from the platen by reverse rotation, and a document discharged from the platen branched from the first conveying path and rotated by the reverse rotation of the conveying means. Provided above the platen for accommodating a second conveyance path that is turned upside down and a document that has been turned upside down by the second conveyance path. And a detection unit that is provided in the second conveyance path and that confirms that the document is ejected to the paper ejection tray, and the first conveyance path and the second conveyance path. It is provided at a branching position, and when feeding a document from the document tray to the transporting unit, document transport on the first transport path is permitted, and when the document is discharged from the platen to the discharge tray, And a conveyance path switching means that shields the first conveyance path on the side of the feeding means and guides the document on the second conveyance path, and has a single forward / reverse rotation motor, and the driving force of this motor. Drive means for transmitting to the feeding means and the conveying means and the motor to rotate the feeding means and the conveying means in the normal direction to convey the original on the original tray to the original setting position, The motor By reversing with reversing the conveying means by switching said transport path switching means on the side for shielding the first conveying path performs a discharge operation of the original, first by the conveying path switching unit 1
After the shielding of the conveyance path is released, the motor is rotated in the forward direction to rotate the feeding means and the conveying means in the forward direction based on the document discharge detection signal to the discharge tray by the detection means, and the sheet is set on the document tray. Since the control means for feeding the next original is provided, the feeding timing is ensured, and there is no risk of the original discharged from the platen coming in contact with the next original, jamming and document jamming are less likely to occur, and the feeding means is also provided. The path between the side and the conveying means can be extremely shortened, and a compact automatic document feeder can be obtained.

[Brief description of drawings]

1 to 8 are views for explaining one embodiment of the present invention. FIGS. 1 and 2 are sectional views showing a schematic structure of an automatic document feeder, and FIGS. FIG. 5 is a sectional view showing the structure of the feeding separating portion, FIGS. 5 to 7 are views showing the structure of the drive mechanism, and FIG. 8 is a timing chart. 1 ... Copier (image forming apparatus) 3 ... Platen glass 5 ... Automatic document feeder 7 ... Document tray 9 ... Feed-out separation unit (feed-out means and feed-out means) 11 ... Paper feed path (first Transport path) 13 …… Transport path switching section (transport path switching means) 17 …… Belt transport section (transport means) 19 …… Reverse path (second transport path) 21 …… Paper ejection tray 47 …… Pickup roller ( Feeding means) 61 …… Switching flapper (transport path switching means) 91 …… Motor (driving means) S ₃ …… Paper discharge sensor (detecting means)

Claims (1)

[Claims] 1. A document tray on which a document is set, a feeding unit for feeding the document set on the document tray by forward rotation, and a contacting / separating unit for bringing the feeding unit into contact with the document only at the time of feeding the document. A first transport path that guides the document delivered by the delivery means to a platen of the image forming apparatus; and a document that is pressed against the platen and guided from the first transport path by forward rotation on the platen. Forward and reverse transport means for transporting to the set position and discharging the original from the platen by reverse rotation, and branching from the first transport path, the original discharged from the platen is inverted upward by the reverse rotation of the transport means. A second conveyance path and a paper ejection tray provided above the platen for storing the originals which are turned upside down by the second conveyance path. And a detection unit provided on the second transport path for confirming that the document is discharged to the discharge tray, and a position provided at a position where the first transport path and the second transport path branch. When the document is sent from the document tray to the transport unit, the document transport on the first transport path is allowed, and when the document is discharged from the platen to the paper discharge tray, And a conveyance path switching unit that guides the original on the second conveyance path while shielding the first conveyance path, and has a single forward / reverse rotation motor, and the driving force of the motor is supplied to the feeding unit and The drive means for transmitting to the conveying means and the motor are rotated in the forward direction to rotate the feeding means and the conveying means in the normal direction, and the original on the original tray is conveyed to the original setting position, and then the motor is rotated in the reverse direction. hand After reversing the conveying means and switching the conveying path switching means to the side that shields the first conveying path, the document discharging operation is performed, and after the shielding of the first conveying path by the conveying path switching means is released. A control means for rotating the motor in the normal direction to rotate the feeding means and the conveying means in the normal direction to send out the next original document set on the original document tray, based on a document discharge detection signal from the detection means to the discharge tray. An automatic document feeder which is characterized in that