JP2980417B2 - Paper feeder of image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeder provided in an image forming apparatus such as a copying machine, a printer, a facsimile, etc., which enables double-sided image formation and multiple image formation.

[0002]

2. Description of the Related Art FIG. 4 shows a conventional example of an image forming apparatus (copier) capable of forming double-sided images and multiple images.

In this image forming apparatus, a sheet material S fed from each of the paper decks 1, 2, 3 is conveyed to a photosensitive drum 5 on which the same image as an original is formed by a predetermined electrophotographic process. Then, after the toner image (latent image) on the photosensitive drum 5 is transferred here, the toner image is conveyed to a fixing device 6 that performs a fixing process of the toner image, and passes through the fixing device 6 to form the first surface (or the first time). To end.

When the single-sided copy mode is selected, the sheet material S after the image formation passes through the upper side of the flapper 7 shown by the solid line and advances as it is in the direction of arrow A by the pair of external discharge rollers 9 to be processed. The paper is discharged onto the paper discharge tray 10 outside.

When the two-sided copying mode is selected, the flapper 7 is in a state shown by a broken line, and the sheet material S after image formation passes through the right side of the flapper 7 by the inner discharge roller pair 11. The vehicle advances in the direction of arrow B and is sent to the vertical path unit 12. Next, after passing through the flapper 13 shown by the solid line, the vehicle enters the reversing path 15. Then, when the rear end of the sheet material S completely passes through the flapper 13, the reversing path roller pair 16 reversely rotates. As a result, the sheet material S becomes an arrow
5 and is guided by the flapper 13 to be directed to the predetermined discharge roller pair 17 of the sheet conveying section 31 as shown in FIG.
Is loaded and stored on the re-feed tray (intermediate tray) 19.

The flapper 13 does not provide resistance to the movement of the sheet material S in the direction of arrow B entering the reversing path 15, but does not provide resistance to the movement of the sheet material S in the direction of arrow C after being reversed. Then, the sheet material S is sent to the sheet material transport unit 31.

When the multiple copy mode is selected, the flapper 13 is switched to a state shown by a broken line by a solenoid (not shown), and the sheet material S sent to the vertical path 12 is transferred to the reverse path 15. The sheet is directly sent to the sheet conveying section 31 without being switched back. The sheet material S is stacked and stored on the re-feed tray 19 by a predetermined discharge roller pair 17.

As shown in FIG. 5, a feeding roller for rotating the sheet S loaded on the sheet re-feeding tray 19 sequentially from the lowermost sheet S is rotated in the direction of the arrow as shown in FIG. 20 and a sheet feed roller pair 21 for separating and feeding the sheet material S sent in a direction indicated by an arrow and fed by the feed roller 20 one by one. The re-feeding tray 19, the feeding roller 20, and the pair of feeding rollers 21 constitute a re-feeding device 30A of the image forming apparatus.

When the sheet material S is stacked on the re-feeding tray 19, the feed-out roller 20 needs to retreat under the re-feeding tray 19 so as not to become a resistor.
Further, when sending out the sheet materials S stacked on the re-feed tray 19, it is necessary to apply a predetermined conveying force.
For this reason, a so-called D-cut roller, in which a part of the outer peripheral surface is cut off in a substantially horizontal shape, is usually used as the feed roller 20. When the rotation of the D-cut roller 20 is stopped so that the cut surface 20A is substantially horizontal on the upper side, the D-cut roller 20 is retracted below the re-feeding tray 19.

The paper feed roller pair 21 includes a paper feed roller 22 and a separate roller 23 driven via a torque limiter (not shown). When one sheet S is fed from the feed roller 20, the sheet is fed as it is, and when a plurality of sheets S is fed, one sheet is separated by friction by the action of the separate roller 23 rotating in the direction of the dashed arrow. Only feed. The sheet material S fed by the sheet feed roller pair 21 is sent to the photosensitive drum 5, and the second surface (or the second time) image formation is performed.

The sheet conveying section 31 for conveying the sheet S onto the re-feeding tray 19 includes a sheet upper guide 25, a plurality of sheet lower guides 26, a plurality of flappers 27, And a pair of discharge rollers 17.

As described above, the plurality of flappers 27 and the pair of discharge rollers 17 are provided in the sheet conveying section 31 because the sheet S has several sizes and the small-sized sheet S is re-fed. If the flight distance to the loading position on the tray 19 becomes longer, the flight of the sheet material S is disturbed by the presence of air, and the loading on the re-feed tray 19 becomes defective, which hinders the image formation on the second side (or the second time). Because it will come. Therefore, a plurality of outlets are required to minimize the flight distance and reduce the influence of disturbance according to the size of the sheet material S. That is, as the size of the sheet material S is smaller, the sheet material S is discharged from the discharge roller pair 17 closer to the flapper 13.

In FIG. 5, reference numeral 29 denotes a side regulating plate, and reference numeral 32 denotes a sheet material holding plate. Side regulation plate 2
Reference numeral 9 denotes a sheet material S which has been sequentially reciprocated in a direction perpendicular to the conveying direction of the sheet material S by a driving source (not shown) and has been discharged.
And a function of adjusting the state of loading on the re-feed tray 19. Further, the sheet material holding plate 32
Has a function of moving the sheet material S stacked on the re-feeding tray 19 in a direction indicated by an arrow by a solenoid (not shown) and pressing the same, and applying a pressure necessary for conveying the sheet material S to the sheet material S.

[0014]

However, like the re-feeding device 30A of the above-described conventional image forming apparatus, D is used as a feeding means for feeding out the sheet materials S stacked on the re-feeding tray 19. When the cut-out feed roller 20 is used, the rubbing force when the outer peripheral surface of the feed roller 20 comes into contact with the sheet material S stacked on the re-feed tray 19 increases, and the load capacity increases. , A large feeding force is required, so the sheet material S
The number of rotations of the feed roller 20 required to reach the sheet feed roller pair 21 also increases to prevent misfeed, and the outer peripheral surface of the feed roller 20 corresponds to the sheet material S.
And the number of times of contact with the sheet material S increases, and there is a disadvantage that roller contamination occurs on the sheet material S.

The D-shaped delivery roller 20
Comes into contact with the sheet material S in a state close to linear contact, and therefore, the sheet material S
They were susceptible to disturbance and had the disadvantage of skewing.

Accordingly, the present invention has been made in view of the above-described circumstances, and is an image capable of re-feeding a sheet material stored in a stacking means without causing dirt, disturbance, skewing and the like. It is an object of the present invention to provide a sheet feeding device of a forming apparatus.

[0017]

According to the present invention, there is provided a stacking means for stacking and storing sheet materials, and a feeding means for sequentially feeding the sheet materials stacked on the stacking means for forming an image. In the sheet feeding device of the image forming apparatus provided with

The feeding means is arranged in parallel with the loading surface of the loading means and has a thick portion which comes into contact with the sheet material when feeding the sheet material, and the sheet material is loaded and stored in the loading means. When the sheet material is stacked and stored in the stacking means, the endless belt comprising a thin portion separated substantially in parallel with the sheet material. The thin portion is stopped while facing the sheet material stacked on the stacking means, and is configured to rotate while bringing the thick portion into surface contact with the sheet material when sending out the sheet material, It is a feature.

Further, the present invention is characterized in that the endless belt comprises a lower layer made of a material having high rigidity and an upper layer made of a material having a high friction coefficient.

In the present invention, the surface of the upper layer of the endless belt has a continuous uneven shape.

[0021]

According to the above construction, the endless belt composed of the thick portion and the thin portion is arranged in parallel with the loading surface of the loading means, and when the sheet material is loaded and stored in the loading means, the endless belt is removed. The unit stops while facing the sheet material stacked on the stacking means so as not to come into contact with the sheet material. Further, when feeding the sheet material, the endless belt is rotated while the thick portion is in surface contact with the sheet material, and the sheet material is fed.

Thus, the sheet material stacked and stored in the stacking means is sent out without causing dirt, disturbance, skewing and the like.

The lower layer of the endless belt uniformly suppresses the elongation during rotation.

Thus, the rotation of the endless belt is stabilized,
Misfeed does not occur.

Further, the endless belt is always in contact with the sheet material stacked on the stacking means at a predetermined pressure regardless of the stacking amount by making the surface of the upper layer uneven.

Thus, the sheet material stacked on the stacking means can be sent out with a stable conveyance force.

[0027]

[0028]

Embodiments of the present invention will be described below with reference to the drawings. First Embodiment FIGS. 1 and 2 show a sheet feeding device of an image forming apparatus according to a first embodiment of the present invention. FIG. 1 is a longitudinal sectional side view, and FIG. 2 is a development view of a main part.

In this embodiment, the same members as those in the above-mentioned conventional example are denoted by the same reference numerals, and the description of those which do not change in function is omitted.

The paper feeding device 30B of the present invention comprises a re-feeding tray 19 as a means for stacking sheet materials S, an endless belt device 33 as a feeding means, and a pair of paper feeding rollers 21 as a paper feeding means. .

The endless belt device 33 includes a drive shaft 36 integrally having a drive pulley 35, a driven shaft 39 integrally having a driven pulley 37, a drive pulley 35 and a driven pulley 3.
7 and a plurality of rubber belts 40 wound therearound.

The endless belt device 33 includes a drive shaft 36 integrally having a drive pulley 35, a driven shaft 39 integrally having a driven pulley 37, a drive pulley 35 and a driven pulley 3.
7 and a rubber belt 40 as a plurality of endless belts.

The rubber belt 40 of the endless belt device 33 has a thin portion (hereinafter referred to as a thin portion) 4 at a part in the circumferential direction.
0A. The rubber belt 40 includes, for example, a lower layer (a pulley contact side) 42 made of a highly rigid material having a wire or the like inside and an upper layer (a sheet material contact side) made of a material having a high friction coefficient between the sheet S and the sheet S. 43. The thin portion 40A is a portion having only the lower layer 42, and the other portion of the rubber belt 40 is a thick portion having the upper layer 43.

The endless belt device 33 is configured such that the thin portion 40A of the rubber belt 40 stops horizontally below the tray loading surface 19 as shown in FIG. 1, that is, the sheet material loaded on the tray loading surface 19 By stopping in a state in which the sheet material S faces the sheet material S while being separated substantially in parallel with the sheet material S, the sheet material S is retracted below the sheet re-feeding tray 19. The retraction of the endless belt device 33 below the re-feeding tray 19 is performed at the time when the sheet material S is stacked on the re-feeding tray 19.

Next, referring to FIG.
The drive mechanism of the pair 3 and the paper feed roller pair 21 will be described.

The rotational power from the image forming apparatus main body (not shown) is transmitted to the input shaft 45. This rotational power is transmitted to the relay shaft 49 via the gears 46 and 47. The rotational power transmitted to the relay shaft 49 is transmitted to another relay shaft 51 via the belt transmission 50, and the gears 52, 5
3 to the feed roller shaft 55, and
The light is transmitted to the separate roller shaft 57 via the second and second rollers 56. The rotational power transmitted to the relay shaft 51 is transmitted to the gears 59 and 6.
0 is transmitted to the drive shaft 36 of the endless belt device 33.

The relay shaft 51 is provided with a control ring 62 having a coil spring inside and a claw 61 on the outer peripheral surface.

The control ring 62 is configured such that the stopper 65 of the electromagnetic solenoid 63 which is in the OFF state has a claw 61 as shown by a solid line.
When engaged, the internal coil spring will be in the open state,
It acts so as not to transmit the torque of the relay shaft 51 to the gear 59.

On the other hand, when the electromagnetic solenoid 63 is turned on to bring the stopper 65 into a suction state (a state shown by an imaginary line),
The internal coil spring is restored and contracted by the release of the claw 61,
This acts to transmit the rotational force of the relay shaft 51 to the gear 59.

In this case, the gear ratio Z of the gears 59 and 60 with respect to the rotation speed n of the relay shaft 51, and the rotation speed nB of the drive shaft 36 required for one rotation of the rubber belt 40 of the endless belt device 33.
Is n = (1 / Z) · nB, and the relay shaft 51 is always
The gear ratio Z is taken into consideration so that the rotation speed n becomes a natural number.
This is because the rotation of the rubber belt 40 is controlled by the electromagnetic solenoid 6.
This is because it depends on the on / off control of No. 3.

Next, the operation of the endless belt device 33 as the feeding means will be described.

When a predetermined number of sheets S on which the image formation on the first side (or the first time) has been completed are stacked on the re-feeding tray 19, the sheet pressing member 32 presses the sheet S with a predetermined pressure. Thereafter, the electromagnetic solenoid 63 is turned on, the stopper 65 is released from the pawl 61 of the control ring 62, and the pawl 61 is released.

When the pawl 61 is released, the control ring 62 is connected to the relay shaft 5.
1 is transmitted to the gear 59, and the drive shaft 36
Rotate, each rubber belt 40 starts rotating in the direction of the arrow in FIGS. 1 and 2, and the sheet materials S stacked on the re-feed tray 19 by the upper layer 43 are sequentially from the lowermost sheet material S. Will be sent out. At this time, the upper layer 43 of the rubber belt 40 makes surface contact with the sheet material S.

After a predetermined time, the electromagnetic solenoid 63
Is turned off, the stopper 65 returns to the claw 61 of the control ring 62.
, The rotational force of the relay shaft 51 is not transmitted to the gear 59 by the control ring 62, and each rubber belt 40 of the endless belt device 33 stops rotating. At this time, the rotation of each rubber belt 40 is stopped so that its thin portion 40A is located below the tray stacking surface 19A of the re-feeding tray 19 as shown in FIG. 1, and the next sheet material S is ready to be fed. <Embodiment 2> FIG. 3 shows Embodiment 2 of the present invention.

This embodiment shows another configuration example of the rubber belt 40 of the endless belt device 33.

The rubber belt 40 of the endless belt device 33
The surface of the upper layer 43 made of a material having a high coefficient of friction is further made uneven so that a constant conveying force can be obtained irrespective of the stacked amount of the sheet material S on the re-feeding tray 19. .

When the stacking amount of the sheet material S on the re-feeding tray 19 increases, the convex portion on the surface of the upper layer 43 is compressed accordingly, but the convex portion receives a reaction force to restore the sheet material. Press S to increase the transport force.

[0048]

As described above, the sheet feeding device of the image forming apparatus of the present invention uses an endless belt as the feeding means for feeding the sheet material stacked on the stacking means, and uses a thick sheet material when feeding the sheet material. Since the endless belt is rotated to feed the sheet material while the meat portion is in surface contact with the sheet material, problems such as dirt, disturbance, and skew of the sheet material can be prevented.

[Brief description of the drawings]

FIG. 1 is a vertical side view of a sheet feeding device of an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a development view showing a driving mechanism of the paper feeding device.

FIG. 3A is a plan view of an endless belt device of a sheet feeding device according to a second embodiment of the present invention, and FIG. 3B is a side view of the endless belt device.

FIG. 4 is a vertical side view of a conventional image forming apparatus (copying machine) capable of forming both-side images and multiple images.

FIG. 5 is an enlarged vertical sectional side view of a sheet re-feeding device provided in the image forming apparatus.

[Explanation of symbols]

 19 Re-feeding tray (loading means) 19A Tray loading surface 21 Paper feed roller pair (feeding means) 30B Paper feeding device 33 Endless belt device (feeding means) 40 Rubber belt 40A Thin portion 42 Lower layer 43 Upper layer 43A Roughness Shaped part S sheet material

Claims (3)

(57) [Claims] An image forming apparatus comprising: a stacking unit for stacking and storing sheet materials; and a feeding unit for sequentially feeding the sheet materials stacked on the stacking device to form an image. In the apparatus, the delivery unit is arranged in parallel with a loading surface of the loading unit.
When the sheet material is fed out
A thick portion that comes into surface contact with the sheet material,
A thin sheet that is separated substantially in parallel with the sheet material when loaded and stored
And an endless belt comprising a meat portion, wherein the endless belt has the sheet material stacked on the stacking means.
When stored, do not touch the sheet material
The thin portion faces the sheet material loaded on the loading means.
Stop when the sheet material is sent out.
It rotates while the thick part is in surface contact with the sheet material.
It is configured urchin It sheet feeding device of an image forming apparatus according to claim. 2. The sheet feeding device according to claim 1, wherein the endless belt includes a lower layer made of a material having high rigidity and an upper layer made of a material having a high coefficient of friction. . 3. The sheet feeder of an image forming apparatus according to claim 2, wherein the surface of the upper layer of the endless belt has a continuous uneven shape.