JPH0585632A - Sheet feeding device and image forming device - Google Patents

Abstract

PURPOSE:To provide a sheet feeding device with which a sheet can be pulled out smoothly without damaging the sheet by providing a returning means having a vertical guide to push back the sheet toward a sheet containing means by getting in contact with a forward end of the sheet protruding from the sheet containing means when the sheet containing means is pulled to a front side end part. CONSTITUTION:A sheet guide 73 comprising a sheet metal for guiding and supporting a paper sheet P taken by a pickup roller 37 to a separation and transfer roller 38 which is integrally formed with a vertical return guide 72 for a returning means is installed at a frame adjacent to a forward end of a sheet feed cassette means 10. A front side end part of the sheet guide 73 is inclined by about 30 deg. to get narrower in the sheet feed direction and bent perpendicularly to form the return guide 72. In such a constitution, as a forward end of the sheet protruded from the sheet feed cassette means is pulled toward the front side of the sheet feed cassette means, it is applied to the guide to be returned toward the sheet feed cassette means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device which uses a front loading type sheet feeding cassette device to separate and feed sheets one by one, and an improvement of an image forming apparatus using the sheet feeding device.

[0002]

2. Description of the Related Art Conventionally, in an apparatus such as an image forming apparatus which needs to be fed, a sheet feeding cassette apparatus for storing sheets does not have a separating function. , The uppermost sheet of the sheets taken out from the sheet feeding cassette device by the separating / conveying roller composed of the sheet feeding roller and the separating roller slidably contacting the sheet feeding roller or the separating sheet. Was separated and supplied to the main body of the device.

[0003]

Conventionally, in an image forming apparatus and an apparatus which generally requires sheet feeding, by a separating roller or a separating sheet of a separating / conveying roller outside a sheet feeding cassette apparatus, The uppermost paper among the papers taken out from the paper feeding cassette device is separated and is fed toward the photoconductor by the paper feeding roller.

For this reason, the second and subsequent sheets of paper that have been taken out of the paper feed cassette device and separated have often had their leading ends protruding from the paper feed cassette device after the completion of paper feeding. Therefore, in a so-called front-loading type sheet feeding cassette device that pulls out the sheet feeding cassette device to the front side of the apparatus main body, when the sheet feeding cassette device is pulled out, such as when replenishing paper, the sheet feeding cassette device remains projected from the sheet feeding cassette device. The leading edge of the paper is often caught in the front frame of the main body and the paper is often damaged.

SUMMARY OF THE INVENTION Therefore, the present invention eliminates the above-mentioned problems, and when a front loading type sheet feeding cassette device is pulled out from the apparatus main body, even if the leading end of the sheet is projected from the sheet feeding cassette device, the sheet is damaged. An object of the present invention is to provide a highly reliable sheet feeding device and an image forming apparatus that can be smoothly drawn out.

[0006]

In order to solve the above-mentioned problems, the present invention solves the above-mentioned problems by accommodating a paper storage means which is detachable from the front side of the apparatus main body, a take-out means for taking out the paper stored in the paper storage means and a take-out means. The sheet is separated by one sheet in the predetermined position direction of the apparatus main body and is fed between the sheet storing means and the sheet feeding means. When the storage means is pulled out, a returning means is provided which has a vertical guide that comes into contact with the front end of the paper protruding from the paper storage means and pushes the paper back toward the paper storage means.

In order to solve the above problems, the present invention provides an apparatus main body having an image forming means, a paper storing means for supplying a sheet to the apparatus main body and being detached from the front side of the apparatus main body, and the sheet storing means. A take-out means for taking out the paper stored in the paper, a paper feeding means for separating and feeding the paper taken out by the take-out means one by one toward the image carrier of the image forming means, and a paper feeding means for feeding the paper from the paper storing means. A vertical guide is provided at the front end portion, which is provided while reaching the paper means, and is brought into contact with the front end of the paper protruding from the paper storage means when the paper storage means is pulled out and pushes the paper back to the paper storage means side. A return means is provided.

[0008]

The present invention is configured as described above, and the leading end of the paper sheet projected from the paper feed cassette device is brought into contact with the guide and pushed back to the paper feed cassette device side in accordance with the operation of pulling out the paper feed cassette device to the front side. .. Therefore, when the paper feed cassette device is pulled out, there is no possibility that the leading end of the paper will be caught by the frame of the main body of the device and damaged, the waste of paper will be eliminated, and the reliability will be improved.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments shown in FIGS.

FIG. 1 shows the internal structure of the entire electrophotographic apparatus that requires paper feeding.
An image forming means 2 for performing exposure, development, transfer, peeling, cleaning, charge removal, fixing, etc. is built in, and an original placing table 3 for placing an original D is provided on the upper surface of the apparatus main body 1. Reference numeral 4 is a document cover.

An automatic double-sided device 100 for reversing the sheet conveyed from the image forming means 2 at the time of double-sided copying is provided in the lower part of the apparatus main body 1. A paper feeding unit 5 that detachably supports first to third paper feeding cassette devices 10a to 10c of a front loading type that stores the paper P to be supplied.
Is provided. Each of the paper feed cassette devices 10a to 10
c has first to third trays 63a to 63c which are raised by the first to third levers 64a to 64c. Further, on the right side of the apparatus main body 1, a paper feed tray 11 for manually feeding the paper P to the image forming means 2 is provided.

Further, a drum-shaped photoconductor 20 which is an image carrier is arranged at substantially the center of the apparatus main body 1, and the photoconductor 20 is surrounded by the photoconductor 20 along its rotation direction, which is well known in the art. Charger charger 21, exposure unit 22 of exposure device 22
a, a developing device 23, a transfer charger 25, a peeling charger 26, a cleaning device 27, and a charge eliminating device 28 are sequentially arranged.

The exposure device 22 illuminates an original D placed on an original placing table 3 provided on the upper surface of the apparatus main body 1 with an exposure lamp 51 whose back is surrounded by a reflector 50.
The light image reflected from the original D is guided to the lens 55 through the first to third reflection mirrors 52 to 54, and then the light image transmitted through the lens 55 is changed to the fourth to sixth reflection mirrors. It is configured so as to be guided to the photoconductor 20 through -56 to 58 in order.

Further, in the main body 1 of the apparatus, paper supplied from the paper feed cassette devices 10a to 10c, the paper feed tray 11, and the automatic double-sided device 100 is provided on the left side of the main body 1 of the device via the photoconductor 20. A paper transport path 31 that leads to the discharge tray 9 is formed.

A register roller pair 32 for aligning the leading ends of the paper P and for carrying the paper in synchronization with the photoconductor 20 is disposed on the upstream side of the photoconductor 20 in the paper transport path 31, and the downstream side thereof. A fixing roller 33 and a paper discharge roller pair 35 are arranged in the printer. Reference numeral 40 is a gate for distributing the paper P conveyed by the conveyance roller pair 34 to either the paper ejection roller pair 35 side or the automatic duplexer 100 side.
A conveyor belt 36 is arranged between the peeling charger 26 and the fixing roller 33.

The sheets 37a to 37c take out the sheets P one by one from the sheet feeding cassette devices 10a to 10c, and feed the sheets to the first to third separating / conveying rollers 38a to 38c.
The first to third pickup rollers are take-out means for supplying the sheet P to the sheet P from the sheet feed tray 11.
Is a fourth pickup roller for picking up the sheets one by one and supplying them to the fourth separating and conveying roller 38d. Then, the paper P taken out from the paper feed cassette devices 10a to 10c by the first to third pickup rollers 37a to 37c is
1 by the first to third separating and conveying rollers 38a to 38c
The sheets are separated one by one and fed into a sheet conveying path 31 that passes through the transfer position of the photoconductor 20. The paper P taken out from the paper feed tray 11 by the fourth pickup roller 37d is transferred by the fourth separating / conveying roller 38d.
The sheets are separated one by one and fed into the sheet conveying path 31.

Here, the first to third pickup rollers 37a to 37c to the first to third separating / conveying rollers 38 are used.
The parts from a to 38c will be described in detail. However, each of the paper feed cassette devices 10a to 10c and the pickup roller 3
Since 7a to 37c and the separating / conveying rollers 38a to 38c have the same structure, they will be described as a common sheet feeding cassette device 10, a pickup roller 37, and a separating roller 38.

The separating / conveying roller 38 is indicated by an arrow s when the first drive shaft 61a is driven by a drive motor (not shown).
Paper feed roller 61 that is rotated in the paper feed direction, and a second drive shaft 62b that is attached to a stationary shaft 62a and is driven by a drive motor (not shown) via a gear 62c and a torque limiter 62d. The separation roller 62 is rotated in the separation direction opposite to the paper feeding direction. Then, a first shaft that supports the stationary shaft 62a and uses the second drive shaft 62b as a fulcrum
The armature 66 is urged in the direction of arrow r by the coil spring 67, so that the separation roller 62 becomes the sheet feeding roller 61.
Being pressed against. However, here, the torque of the torque limiter 62d is smaller than the frictional force between the paper feed roller 61 and the separation roller 62 or the frictional force between the paper P and the separation roller 62 that are conveyed in one sheet taking, It is set to be larger than the frictional force between the sheets P.

Further, the pickup roller 37 is a second arm.
While being supported by the support shaft 70 via the frame 68, the first
Timing belt 71d, a second pulley 71b, and a third pulley 71a that are stretched between the second pulley 71b supported by the fulcrum shaft 68a of the second arm 68 and the second pulley 71a.
The first drive shaft 61a is rotated in the arrow v direction, which is the paper feeding direction, via the second timing belt 71e that is stretched between the pulleys 71c.

The frame adjacent to the front end of the paper feed cassette device 10 is made of sheet metal and is a pickup roller.
The paper P taken out by the roller 37 is separated and conveyed by the roller 38.
A sheet guide 73, which is integrally formed with a vertical return guide 72 which is a return means, is attached. That is, the front end of the sheet guide 73 is inclined at about 30 [°] so as to become narrower in the sheet feeding direction, and is further bent vertically to form a return guide 72.

On the paper take-out side of the automatic duplexer 100, a fifth pickup roller 102 for taking out the paper from the paper stacking unit 101 and the paper from the fifth pickup roller 102 are fed to the paper feed path 31. A fifth separating / conveying roller 38e for feeding is arranged. Further, 103 is a reversing conveyance path for conveying the sheet conveyed by the gate 40 to the automatic duplexer 100 side to the sheet stacking section 101.

Next, the operation will be described. At the start of copying, the document D is placed on the document table 3 and the number of copies is
Copy conditions such as copy magnification, paper size, and image density are input from an operation panel (not shown). And copy
When the copy operation is started by turning on (not shown),
The photoconductor 20 is sequentially charged, exposed, and developed by the image forming means 2 in accordance with the rotation of the photoconductor 20 to form a developed image.

On the other hand, in the paper feeding unit 5, paper is fed from any one of the first to third paper feeding cassette devices 10a to 10c selected by the paper size setting. That is, the tray 6 is rotated by the lever 64 rotating in the arrow w direction.
3 is moved up, the sheet P contacts the pickup roller 37, and then the first drive shaft 61a is rotated in the direction of arrow s by the drive of a drive motor (not shown), and the second drive shaft 62 is moved.
b is rotated in the direction of arrow t.

As a result, a torque in the direction of arrow s is applied to the paper feed roller 61, and a torque in the direction of arrow u is applied to the separation roller 62 via the gear 62c and the torque limiter 62d. Further, the pickup roller 3 is mounted on the first drive shaft 61a via the first to third pulleys 71a to 71c and the first and second timing belts 71d and 71e.
7 is rotated in the direction of arrow v. As a result, the uppermost sheet from the paper feed cassette device 10 is taken out in the direction of the separating / conveying roller 38, and when the sheets are taken out in multiple, the separating / conveying roller 38 separates them.

That is, in the separating / conveying roller 38, the rotating force in the arrow s direction and the arrow u direction are applied to the sheet feeding roller 61 and the separating roller 62 before passing the sheet P, but the separating roller 38 is separated. Since the frictional force between the sheet feeding roller 61 and the separating roller 62 is larger than the rotational force of the torque limiter 62d of the roller 62, the separating roller 62 is attached to the sheet feeding roller 61. It is driven and rotated in the direction of arrow x. After that, when one sheet of paper P is taken out, the paper P is kept as it is by the rotation of the paper feed roller 61 in the direction of the arrow s and the registration roller pair 32
Paper is fed in the direction. However, also at this time, the separation roller 62 is compared with the rotation force of the torque limiter 62d by the feed roller 61.
Since the frictional force between the paper P and the paper P to be fed is larger, the paper P is driven and rotated in the arrow x direction. On the other hand, when multiple sheets are taken, the separating roller 62 is rotated in the direction of arrow u because the rotational force by the torque limiter 62d of the separating roller 62 is larger than the frictional force between the sheets. Only the uppermost sheet is fed, and the second and subsequent sheets are pushed back into the sheet feeding cassette device 10. However, at this time,
After the second sheet of paper P is separated from the separation roller 62,
Since it is pushed back by the inertial force in the direction of the sheet feeding cassette device 10, it may not be able to return to the inside of the sheet feeding cassette device 10 and may be stopped while the front end is projected from the sheet feeding cassette device 10.

Then, the uppermost sheet P is sequentially fed from the sheet feeding cassette device 10, and when all required feeding is completed, the lever 64 is rotated in the direction opposite to the arrow w direction and the tray 63 is lowered. At the same time, the motor is stopped and the paper feed roller 61, the pickup roller 37, and the separation roller 6
2 is stopped. At this time, the paper P is separated by the separation roller 62.
If the paper has not been completely returned into the paper feed cassette device 10, as shown in FIG.
It is projected from 0.

On the other hand, the paper P fed by the separating / conveying roller 38 is temporarily stopped at the position of the registration roller pair 32, and is synchronized with the photoconductor 20 in synchronization with the developer image on the photoconductor 20 by the image forming means 2. The developer image on the photoconductor 20 is transferred to the space between the transfer chargers 25. The sheet P on which the developer image is transferred is separated by the peeling charger 26 from the photoconductor 20.
The image is separated from the sheet, conveyed by the conveying belt 36, sent to the fixing roller 33 to fix the image, and ejected in the direction of the sheet ejection tray 9. After the transfer is completed, the photoconductor 20 can be copied next through the cleaning device 27 and the static eliminator 28.

During this period, when it is necessary to replenish the paper or replace the paper, the paper feeding cassette device 10 is pulled out from the paper feeding unit 5, but the paper P is fed to the paper feeding cassette device 1.
0 is not completely housed and the tip is seat guide 7
When the sheet P remains on the sheet 3, the sheet P abuts the vertical return guide 72 as the sheet cassette device 10 is pulled out to the front side as shown in FIG. 3, and receives a reaction force from the return guide 72. The sheet P is gradually slid in the direction of the arrow y to a position where it is removed from the return guide 72 by the waist of the sheet P. Therefore, the paper P
Even if the leading edge remains on the sheet guide 73, the paper P is returned to the paper feeding cassette 10 side when the paper feeding cassette 10 is pulled out, so the paper P is placed on the front frame of the paper feeding unit 5. The paper feed cassette device 10 can be smoothly pulled out without being caught.

With this structure, the paper feed cassette device 1
With the operation of pulling out 0, the leading end of the paper P is returned to the guide 72.
Since it is pushed back to the paper feed cassette device 10 side by the operation, when the paper feed cassette device 10 is pulled out, the paper P
The leading end is not caught by the front frame of the paper feeding unit 5 and the paper is not wasted, so that the paper feeding cassette device 10 can be smoothly attached and detached, and the reliability is improved.

The present invention is not limited to the above-described embodiment, but can be changed within the scope of the invention, and the material of the returning means and the inclination angle with respect to the sheet feeding direction can be arbitrarily set. However, the separating means may be a separating sheet made of a friction member.

[0031]

As described above, according to the present invention, when the front loading type paper accommodating means is pulled out, even if the front end of the paper is projected from the paper accommodating means, the paper accommodating means is pulled out from the apparatus main body. With the operation, the paper can be pushed back to the paper storing means by the returning means.
There is no risk that the paper will be caught by the front frame and damaged when the paper storage means is pulled out, waste of the paper due to damage is eliminated, and the reliability of the apparatus can be improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an entire apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic explanatory view showing a sheet feeding device according to an embodiment of the present invention.

FIG. 3 is a top view showing a sheet guide according to an embodiment of the present invention.

FIG. 4 is a schematic explanatory view showing a state in which the leading end of the sheet at the end of sheet feeding is projected from the sheet feeding cassette device according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Device main body 2 ... Image forming means 5 ... Paper feed unit 10 ... Paper feed cassette device 37 ... Pickup roller 38 ... Separation / conveyance roller 72 ... Return guide 73 ... Sheet guide

Claims (2)

[Claims] 1. A paper storage means that is detachable from the front side of the apparatus main body, a take-out means for taking out the paper stored in the paper storage means, and the paper taken out by the take-out means in a predetermined position direction of the apparatus main body. A sheet feeding means for separating and feeding the sheets one by one, and a leading end of the sheet provided between the sheet storing means and the sheet feeding means and protruding from the sheet storing means when the sheet storing means is pulled out. A paper feeding device, comprising: a return guide having a vertical guide for pushing back the paper toward the paper storing means at the front end. 2. An apparatus main body having an image forming means, a paper storing means for supplying paper to the apparatus main body and being detached from the front side of the apparatus main body, and a take-out means for taking out the paper stored in the paper storing means. A sheet feeding means for separating and feeding the sheets taken out by the taking-out means sheet by sheet in the direction of the image carrier of the image forming means; and a sheet feeding means provided between the sheet storing means and the sheet feeding means. And a return means having a vertical guide at the front end for pushing the sheet back toward the sheet storage means when the leading edge of the sheet protruding from the sheet storage means is brought into contact when the sheet storage means is pulled out. Image forming apparatus.