JPH085169Y2 - Document feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a sheet feeding unit and a sheet separating unit by rotating a single driving unit forward and backward, a pair of registration rollers for waiting the separated sheet, and a pair of registration rollers. The present invention relates to a document feeder which selects and drives a conveying unit that conveys a sheet and positions it at a predetermined position according to a rotation direction.

[Prior Art] By rotating a single drive means forward and backward, a feeding means for the sheets stacked on the stacker, a separating means for separating the fed paper, and a posture of the separated sheets are made to stand by. In a document feeding apparatus in which a pair of registration rollers and a conveyance unit that receives and conveys the sheet and positions it at a predetermined position are selected and driven according to a rotation direction, conventionally, the feeding unit and the separating unit side are in operation. There was no fixing means for preventing the registration roller pair and the conveying means from rotating.

[Problems to be Solved by the Invention] By rotating such a single drive means in the forward and reverse directions, a sheet feeding means and a separating means, a pair of registration rollers for waiting the sheet, and a conveyance localization to a predetermined position. In the document feeding apparatus in which the transporting means to be driven is selectively driven, a one-way clutch is interposed at each of important points of the driving force transmission paths, and the registration roller pair is operated while the feeding means and the separating means are operating. The conveying means side is free in its operating direction, and the feeding means side is still free in its operating direction while the pair of registration rollers is operating.

Therefore, assuming a case where the sheet sent out from the separating unit hits the nip point of the downstream registration roller pair, the registration roller pair is normally immovable to adjust the posture of the sheet, and the front edge of the sheet is fixed. The rear portion of the receiving paper sheet is in a standby state with a curve drawn in the resist space.

However, since the pair of registration rollers is in the free state as described above with respect to the paper traveling direction, depending on the stiffness of the paper that bites into the nip point,
The action of rotating the pair of registration rollers may be exerted. Since the registration roller pair and the conveyance means belong to the same power transmission system, if the registration roller pair is slightly shaken by the stiff paper, it is actually localized at a predetermined position by the conveyance means. However, there is a problem in that a good image forming process cannot be performed due to the positional deviation of the preceding paper.

It has also been observed that when a sheet is interposed between the platen of the image forming apparatus and the conveying means, the frictional force between the conveying means and the platen decreases, and the above-mentioned rotation easily occurs. .

[Object of the Invention] The present invention has been made in view of the above-mentioned problems of the prior art, and includes a sheet feeding unit, a separating unit, a registration roller pair, and a conveying unit, and a single driving unit. The position of the sheet that can be switched by reverse rotation and is positioned on the platen of the image forming apparatus without shaking the registration roller pair and the conveying unit side even when the sheet is strong while the feeding unit and the separating unit are operating. An object of the present invention is to provide a document feeder that does not cause misalignment.

[Means for Solving the Problems] The gist of the present invention for achieving the above object is to provide a means for feeding an original stacked on a paper feed stacker and a resist for temporarily holding the original from the feeding means. The roller means and the document from the registration roller means are conveyed,
Documents that have a conveyance unit that stops conveyance at a predetermined position on the platen and discharges from the platen after exposure, and a control unit that sequentially controls the feeding, standby, conveyance, exposure, and discharge of sheets on the sheet stacker In the paper feeding device, a brake means is provided in a transmission means that connects the registration roller means and the conveying means to the same driving means, and the control means is arranged to operate the feeding means while the conveying means is stopped. The present invention resides in a document feeder configured to operate the brake means when the control means stops the conveying means at a predetermined position and when the feeding means operates.

[Operation] The sheets stacked on the stacker are fed out by the feeding means driven by one direction of the driving device, for example, forward rotation, and separated into one sheet by the separating means also driven by forward rotation, and the registration rollers. Put the front edge of the paper against the pair and arrange the posture to stand by.

During the above operation, the electromagnetic means holds and fixes the shaft of the registration roller pair, and the conveyance means connected to the same driving force transmission system as the registration roller pair is also fixed at the same time, and does not fluctuate, and the conveyance means forms an image. It does not cause misalignment of the preceding paper that has been localized on the platen of the device.

When the processing of the preceding sheet by the image forming apparatus is completed, the driving device rotates in the reverse direction, that is, in the negative direction, and at the same time, the holding of the registration roller pair by the electromagnetic means is released, and the preceding sheet is conveyed. The sheet that has been waiting until then is delivered by the pair of registration rollers that have simultaneously been started to rotate, and then the sheet is delivered to the transporting means and localized at a predetermined position.

Embodiments Various embodiments of the present invention will be described below with reference to the drawings.

In this embodiment, as shown in FIG. 1, a document feeding device 10 for feeding a document sheet onto a platen 2 of an electronic copying apparatus 1 will be described.

The document feeder 10 includes a paper feed stacker 11 on which documents are placed.
And a feeding unit 20 for separating the documents set in the paper feeding stacker 11 one by one and feeding them to the platen 2, and a feeding unit for feeding the papers fed from the feeding unit 20 along the platen 2. And a sheet discharging section 110 for reversing and ejecting the document conveyed on the platen 2 by the conveying section 100, and a sheet discharging stacker 12 for storing the document discharged from the sheet discharging section 110. 2, a control device (not shown), and a drive device shown in FIG.

The feeding section 20 includes paper feed guides 21 and 22 and a paper feed stacker.
A feeding means for feeding the document set on 11, for example, a pickup roller 23, an empty sensor 24 for detecting whether or not a document is set on the paper feed stacker 11, and a feeding device which rotates in the paper feeding direction and constitutes a separating means. A paper roller 25, a separation roller 26 that is a structure of a separation unit that rotates in the direction of moving away from the second paper and below, a size detection sensor 27 for detecting the size of the document in the width direction, and a paper If it is not detected, a jam detection sensor 28 that issues a jam detection signal
And a pair of registration rollers 29, 29a.

The paper feed roller 25 is attached to the rotary shaft 40 shown in FIG. 2 via a one-way clutch. Further, the paper feed roller 25 and the separation roller 26 constitute a separation means.

Further, the pickup roller 23 has its rotating shaft 42 supported by a pair of swing arms 44, the base end of which is attached to the rotating shaft 40 via a spring clutch 43. And gear 58,
The rotational force of the drive motor 30 is transmitted by 59 and 60. The spring clutch 43 is a drive motor 30 described later.
When a normal load is applied and a load larger than a predetermined value is applied, it spins.

The transport unit 100 includes a pair of rollers 101 and 102, a transport belt 103 stretched between the rollers 101 and 102, and a plurality of press rollers 104 that press the transport belt 103 against the platen 2 side. There is.

As shown in FIG. 2, a pulley 46 is attached to the rotary shaft 45 of the roller 101, and a pulley 48 is attached to the rotary shaft 47 of the roller 102.

The paper discharge unit 110 is configured to discharge paper discharge guides 111 and 11 that form a paper discharge path.
2, a synthetic resin sheet 113 attached to the lower end of the paper ejection guide 112, and a conveyor belt attached to the paper ejection guide 112.
Pinch roller 114 pressed against 103 and paper ejection sensor 115
A sheet discharging roller 116 and a leaf spring 117 pressed against the sheet discharging roller 116.

It should be noted that, as shown in FIG.
Pulley 50 is attached to 9 and this pulley 50
8 and the belt 51 are connected.

The control device is provided with, for example, a microcomputer, and drives and controls a drive motor 30 and the like, which will be described later, according to signals from the sensors 24, 27, 28, 115 and signals from the copying apparatus 1.

As shown in FIG. 2, the drive device includes a drive motor 30 that can rotate forward and backward, a pulley 32 attached to a rotation shaft 31 of the drive motor 30, a timing belt 35 that connects the pulley 32 and the pulley 34, A gear 38 attached to the rotating shaft 33 via a spring clutch 37, and a gear 39 meshing with the gear 38.
A gear 41 which meshes with the gear 39, a gear 52 which meshes with the gear 41, a gear 54 which meshes with the gear 52 and is mounted on the rotary shaft 53 of the separation roller 26, and a rotary shaft via a one-way clutch 36A. Gear 36 attached to 33 and registration roller 29
The gear 56 that is attached to the rotating shaft 55 of the and meshes with the gear 36.
And a gear 57 that meshes with the gears 46 and 56.

As described above, the one-way clutch 36A is interposed in the gear 36 so as not to transmit the rotation to the gear 56 when the drive motor 30 rotates in the normal direction.

Further, one end of the rotation shaft 55 of the registration roller 29 penetrates the device frame 95 as shown in the figure, and holds the rotation shaft 55 at its end in a timely manner to serve as an electromagnetic brake means for stopping the rotation of the registration roller 29. An electromagnetic brake 90 is provided.

The spring clutch 37 is designed to idle when a load larger than a predetermined value is applied when the drive motor 30 rotates in the reverse direction.

The forward rotation of the drive motor 30 causes the pickup roller 2
3, a member for transmitting the rotational force of the drive motor 30 to the paper feed roller 25 and the separation roller 26 is used as the first transmission means, and the drive motor 30
A member for transmitting the rotational force of the drive motor 30 to the registration roller pair 29, the conveyance belt 103, and the paper discharge roller 116 by the reverse rotation of is used as the second transmission means.

As shown in FIGS. 1 and 2, the opening / closing means 70 for opening / closing the feeding passage 21 is provided with a feeding passage opening / closing shaft 71 in a position parallel to and separated from the rotation shaft 42 of the pickup roller 23. A pair of stopper members 72 are fixed to the shaft 71, and an open / close driven arm 73 is fixed to at least one end of the shaft 71. The stopper member 72 is always provided at the tip of the open / close driven arm 73. The direction of closing the feeding passage 21, that is, the first
In the figure, an urging spring 74 for urging clockwise is provided.

On the other hand, an opening / closing drive arm 80 is fixedly provided at least at one end of the rotary shaft 40 of the paper feed roller 25 via a spring clutch 81, and a system for engaging with the opening / closing driven arm 73 at the tip thereof. Dowel pin 82 is planted.

Next, the operation will be described with reference to the time chart of FIG.

First, when the document is set on the paper feed stacker 11 with the front side facing down, the empty sensor 24 detects the document and the document can be automatically fed.

When a paper feed button (not shown) is pressed in such a state, the electromagnetic brake 90 is turned on and the drive motor 30 is normally rotated.

As a result, the one-way clutch 36A becomes idle,
The driving force is not transmitted to the registration roller shaft 55 and the belt roller shaft 45, and the pulley 32, the timing belt 35, and the pulley
The rotating shafts 40, 53 rotate in the forward direction via the gears 34, the gears 38, 39, 41, 52, 54. (Indicated by a solid line arrow in FIG. 2.) The swinging arm 44 descends due to the normal rotation of the rotary shaft 40, and the pickup roller 23 comes into contact with the document. Therefore, the spring clutch 43 is loaded and slips, and the state where the pickup roller 23 contacts the document is maintained.

Further, the normal rotation of the rotary shaft 40 causes the separation roller 26 to rotate in a direction in which the feeding of the original is blocked, so that the original following the original fed by the paper feed roller 25 is rejected and the original is separated into one sheet.

The original separated into one sheet hits the nip points of the registration rollers 29, 29a, and temporarily stops there and stands by. During this operation, the electromagnetic brake 90 continues to be in the ON state, and the registration rollers 29 and 29a are kept stationary. And
It is turned off for some time, for example, 400 mmsec after the stop signal of the drive motor 30. Then, after some time, a reverse rotation command is issued to the drive motor 30.

When the drive motor 30 rotates in the reverse direction (indicated by a dotted arrow), the driving force is transmitted to the roller 101 of the conveyance unit 100 via the gears 36, 56, and 46, and the original document is transferred from the registration roller 29 to the conveyance unit 100.
Is delivered to the platen 2 and stopped at a predetermined position. Simultaneously with this stop, the electromagnetic brake 90 is turned on again, the system of the second transmission means is immediately stopped, and the document is not displaced.

Then, after the copying operation is executed, a reverse rotation command is issued to the drive motor 30 again, and the document on the platen 2 is ejected from the paper ejection unit 11
Emitted from 0. During this discharging operation, on the other hand, the next original document that is already waiting in the registration roller 29 is fed onto the platen 29 by the transport unit 100.

Next, an ON command is issued to the electromagnetic brake 90, a normal rotation command is issued to the drive motor 30 after the suspension, and the forward rotation causes a series of operations such as feeding out and separating documents from the stacker 11. . Then, during this period, a copy process is performed on the original document sent to the platen 2 earlier.

 Next, a second embodiment will be described with reference to FIG.

In this embodiment, the rotation axis of the registration roller 29 is as shown in the figure.
55 is provided with a gear 97, and an electromagnetic clutch 96A that meshes with the gear 97 is provided on the shaft 33.

The operation is such that when the document is conveyed by the reverse rotation of the drive motor 30 and a stop command is received at a predetermined position, an ON command is issued to the electromagnetic clutch 96A at the same time, and the drive motor 3
The load on the 0 side is immediately applied, the conveyance unit 100 is immediately stopped, and the document is accurately localized.

[Advantages of the Invention] According to the present invention, the document feeding means stacked on the sheet feeding stacker, the registration roller means for temporarily waiting the document from the feeding means, and the document fed from the registration roller means are conveyed. , A conveyance means for stopping the conveyance to a predetermined position on the platen, and ejecting it from the platen after exposure, and a control means for sequentially controlling the feeding, standby, conveyance, exposure, and ejection of the sheets on the sheet stacker. In the document feeding device, a brake means is provided in a transmission means that connects the registration roller means and the conveying means to the same driving means, and the control means operates the feeding means while the conveying means is stopped. The control means activates the brake means when stopping the conveying means at a predetermined position and when operating the feeding means. Therefore, during the operation of the feeding means and the separating means, even if a stiff paper hits the registration roller pair, the registration roller pair and the conveyance means side do not shake, and the paper positioned on the platen of the image forming apparatus is not shaken. There is no misalignment.

[Brief description of drawings]

1 to 3 show a first embodiment of the present invention. FIG. 1 is a sectional view showing a schematic structure of a document feeding device, and FIG. 2 is a structure of a driving device of the document feeding device. FIG. 3 and FIG. 3 are timing charts of the operation, and FIG. 4 is a configuration diagram of the driving device of the second embodiment. 10: Document feeder 20: Feeding section 23: Pickup roller (feeding means) 25: Paper feeding roller (separating means) 26: Separation roller (separating means) 29, 29a: Registration roller pair 30 ...... Drive motor 33 …… Rotary shaft 36 …… Gear 36A …… One-way clutch 37 …… Spring clutch (one-way clutch) 40 …… Rolling shaft of paper feed roller 55 …… Rotary shaft of registration roller 90 …… Electromagnetic Brake (electromagnetic braking means) (first embodiment) 96A ... Electromagnetic clutch (electromagnetic braking means) (second embodiment) 97 ... Added gear (electromagnetic braking means) (second embodiment) 100 ... Transport Department (transportation means)

Claims (1)

[Scope of utility model registration request] 1. A feeding means for feeding a document stacked on a sheet feeding stacker, a registration roller means for temporarily holding the document from the feeding means, and a document fed from the registration roller means for feeding at a predetermined position on a platen. In a document feeding apparatus having a control means for stopping the conveyance to and discharging from the platen after exposure, and sequentially controlling the feeding, standby, conveyance, exposure, and discharge of sheets on the sheet stacker, A braking means is provided in a transmission means that connects the registration roller means and the conveying means to the same driving means, and the control means is configured so that the feeding means operates while the conveying means is stopped. The braking means is operated when the conveying means is stopped at a predetermined position and when the feeding means is operated. Document feeder.