JPH08319064A - Double-sided device - Google Patents

Abstract

(57) [Summary] [Purpose] Paper can be reliably fed to the double-sided tray for a long period of time, and paper can be re-fed without jamming. [Structure] A plurality of grooves 20 parallel to the axis of the feed roller 13 are formed on the outer peripheral surface of the feed roller 13, and the tip end of the elastic guide 14 is fitted into the groove 20 and follows the rotational direction of the feed roller 13. And change the direction.
As a result, each time the rotation direction of the feed roller 13 changes, the tip end portion of the elastic guide 14 is fed by the feed roller 1.
Since the direction changes in the state of being fitted in the groove 20 of No. 3, the direction changes with a smaller amount of bending as compared with the case where the groove 20 is not formed by the depth of the groove 20 in which the tip end thereof is fitted. Therefore, the elastic guide 1 is reduced by the amount of bending.
The durability life up to the cutting of No. 4 is extended.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a copying machine, a printer,
The present invention relates to a double-sided device provided in an image forming apparatus such as a facsimile and used when forming images on both sides of a sheet.

[0002]

2. Description of the Related Art A double-sided device used to form an image on both sides of such a sheet is, for example, a double-sided tray for storing the sheet on which an image is formed on one side, and a sheet for feeding the sheet into the double-sided tray. There is one including a feed roller rotatable in one direction and a second direction for feeding a sheet from the double-sided tray, and a separation roller rotatable in pressure contact with the feed roller.

The feed roller and the separation roller are formed of, for example, a rubber elastic body, and when the sheets on which an image is formed on one side are stored in a double-sided tray, the feed roller is normally rotated in the first direction. Function as a transport roller, and the separation roller rotates following the feed roller to function as a transport roller. When the paper stored in the double-sided tray is re-fed, the feed roller reversely rotates in the second direction to function as a calling roller and a paper feeding roller, and the separation roller is stopped. And play the role of the original separation roller.

As described above, in the case of the feed roller of the type described above, it has both the stacking function and the re-feeding function. However, in such a feed roller, the elastic guide (such as a polyester film) is formed on the outer peripheral surface thereof. Elastic piece)
There is one in which the leading end portion of the sheet is always abutted to improve the sheet transportability and sheet feeding ability by the action of the elastic guide (for example, JP-A-63-154539 and JP-A-63-154541). See the bulletin).

Like the elastic guide 4 shown in FIGS. 7 and 8, such an elastic guide has its tip 4a constantly in contact with the feed roller 3, and the tip 4a is in the rotational direction of the feed roller 3. Depending on the, the direction is changed to the left or right, thereby improving the transportability of the paper.

That is, when the sheets 4 are stacked with the front end 4a of the elastic guide 4 facing to the left as shown by the phantom line in FIG. 8, the rear end of the paper P fed into the double-sided tray 2 is set to the front end of the elastic guide 4. 4a is pressed against the outer peripheral surface of the feed roller 3, and the rear end of the paper P is not caught by the guide plate 7 due to the conveying force of the feed roller 3 and the double-sided tray 2
It is designed to fall on the bottom plate 5 of the. Further, at the time of re-feeding with its leading end 4a facing the right side as shown by the solid line in FIG. 8, the paper P fed from the double-sided tray 2 is guided to the contact portion (nip) between the feed roller 3 and the separation roller 6. Work.

[0007]

However, when the feed roller 3 rotates in the arrow B direction as shown in FIG. 9 and then rotates in the arrow A direction as shown in FIG. From the position shown to the position shown by the solid line, the tip 4
A changes its direction while being largely bent as shown in the figure. This elastic guide 4 changes its direction while bending,
The same occurs not only when the feed roller 3 changes its rotation direction in the arrow A direction, but also when it changes its rotation direction in the opposite arrow B direction (from the position where the tip end portion 4a is indicated by the solid line to the position indicated by the imaginary line). Change).

The change of the direction of the elastic guide 4 while causing the flexure is repeated every time the stack operation is changed to the sheet re-feeding operation or the opposite operation is changed during double-sided image formation. In FIG. 10 (a)
As shown in FIG. 10, a crack Cr may be generated in the tip end portion 4a of the elastic guide 4, and the portion may be cut as shown in FIG. 10B. When the tip portion 4a of the elastic guide 4 is cut in this way, the tip portion 4a is cut off as shown in FIG.
Since it does not come into contact with the outer peripheral surface of the feed roller 3 shown in FIG. 2, the elastic guide 4 cannot guide the paper P or cannot perform the function of pressing the paper P against the outer peripheral surface of the feed roller 3. appear.

The present invention has been made in view of the above problems, and it is possible to reliably feed a sheet having an image formed on one side thereof to a double-sided tray for a long period of time.
The purpose is to prevent the paper stored in the double-sided tray from becoming a jam when it is re-fed.

[0010]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a double-sided tray for accommodating a sheet having an image formed on one side, a first direction for feeding the sheet into the double-sided tray, and its direction. A double-sided device including a feed roller rotatable in a second direction for feeding a sheet from a double-sided tray, and an elastic piece arranged such that a tip end portion thereof abuts on an outer peripheral surface of the feed roller. A plurality of grooves parallel to the axis of the feed roller are formed on the outer peripheral surface of the feed roller, and the tip end of the elastic piece is fitted into the groove so that the direction changes in accordance with the rotation direction of the feed roller. .

[0011]

According to the double-sided device constructed as described above, the tip end portion of the elastic piece, which abuts the outer peripheral surface of the feed roller, has the rotation direction of the feed roller from the first direction to the second direction or vice versa. The depth of the groove in which the tip of the feed roller fits into the groove formed on the outer peripheral surface of the feed roller as it changes each time it changes. Since the direction changes with a smaller amount of bending as compared with the case where the groove is not formed in the feed roller, the durability life up to cutting is extended by the amount of the amount of bending reduced.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing an embodiment of a double-sided device according to the present invention together with a part of an image forming apparatus. This double-sided device 1 has a sheet P having an image formed on one side.
, A first side indicated by an arrow A for feeding a sheet into the double-sided tray 12, and a second direction opposite to the arrow A for feeding a sheet out of the double-sided tray 12. The feed roller 13 and an elastic guide 14 that is an elastic piece arranged so that the tip end portion thereof abuts on the outer peripheral surface of the feed roller 13.

The double-sided tray 12 has a movable bottom plate 15 on which a sheet P having an image formed on one side is stacked.
The bottom plate 15 is moved to the bottom plate 1 by the bottom plate moving means 11.
The sheet P placed on the sheet 5 is rotated about the fulcrum 21 to the raised position indicated by the phantom line in FIG.

The double-sided device 1 also includes a double-sided tray 12
The paper P fed by the feed roller 13 and the separation roller 42 that is pressed against the feed roller 13 is rotated toward and away from each other in the front and back directions (jogging operation) in FIG. A pair of side fences (not shown) that align their positions, and a double-sided tray 1
Also provided is an end fence 43 that can reciprocate in the left-right direction in FIG. 1 for aligning the position of the front end portion (which becomes the rear end at the time of re-feeding) of the paper P fed onto the sheet 2.

As shown in FIG. 2, the feed roller 13 is attached to the feed roller shaft 16 so as to come into contact with the vicinity of the conveyance center of the paper P to be fed with a predetermined width, and the feed roller 13 is provided on the outer peripheral surface thereof. Groove 2 parallel to the axis of shaft 16
A plurality of 0s are formed over the entire circumference, and the tip end portion 14a of the elastic guide 14 is fitted into the groove 20 of the elastic guide 14 so as to follow the rotational direction of the feed roller 13 and change its direction.

The elastic guide 14 is formed of a flexible film material such as polyester, and has a width substantially corresponding to the length of the feed roller 13 in the axial direction, and its tip portion. Is in contact with the outer peripheral surface of the feed roller 13 with a contact pressure that does not hinder the rotation of the feed roller 13 due to the elastic force of the material itself.

This double-sided device 1 includes a double-sided tray 12 shown in FIG.
When feeding the paper P from the feed roller 13, before feeding the paper P on the double-sided tray 12 to the feed roller 13 by raising the tip side of the bottom plate 15 by the bottom plate moving means 11, the feed roller 13 is opposite to the arrow A. In the second direction to change the direction of the tip end portion of the elastic guide 14 to the right direction (the opposite direction to that shown in the figure).

FIG. 3 is a perspective view showing a mechanism for operating the feed roller 13 and the bottom plate 15 as described above. This mechanism drives the feed roller 13 and the bottom plate moving means 11 by a motor 22 which is the same drive source. The bottom plate moving means 11 applies a rotational force from the motor 22 to the speed reduction mechanism 23.
To the lever holding shaft 39, and the pressure lever 37 fixed thereto is rotated to rotate the bottom plate 15 around the fulcrum 21 (FIG. 1).

When the motor 22 is rotated to rotate the feed roller 13 in the second direction indicated by the arrow B, the bottom plate moving means 11 is operated via the speed reduction mechanism 23, and the bottom plate 15 is moved.
Is moved by the deceleration mechanism 23 after a delay to an ascending position (the position changes depending on the number of sheets of paper loaded on the bottom plate 15) shown by a virtual line in FIG. The speed reduction mechanism 23 is composed of a large number of gears arranged in a train wheel as shown in FIG. 3, and the drive gear 2 fixed to the rotation shaft of the motor 22.
4, the large diameter portion of the first idle gear 25 meshes with the small diameter portion of the first idle gear 25, and the large diameter portion of the second idle gear 26 meshes therewith.

Further, a third idle gear 27 meshes with the small diameter portion of the second idle gear 26, and an input gear 28 meshes with the third idle gear 27. A gear 31 for sequentially transmitting the rotational force from the motor 22 to another drive system is meshed with the input gear 28, and gears 32 and 33 are sequentially meshed with it.

A cam 29 is attached to the input gear 28 via a clutch 30 that idles when a predetermined load or more is applied, and a pin 34 is attached to the cam 29 at a position eccentric from the rotation center. , One end of a pressure spring 35 is attached to the pin 34. Then, the other end of the pressure spring 35 is attached to a pressure arm 36 fixed to one end of a lever holding shaft 39 rotatably held by a fixing portion of the double-sided device. The lever holding shaft 3
The numeral 9 fixes one end of a pressure lever 37 for rotating the bottom plate 15 at a position substantially corresponding to the center of paper conveyance.

On the other hand, a roller driving gear 38 meshes with the small diameter portion of the second idle gear 26, and the roller driving gear 38 is one end of the feed roller shaft 16 rotatably held by the fixed portion of the double-sided device 1. And the feed roller 13 is fixed to the feed roller shaft 16.

The image forming apparatus having the double-sided device 1 shown in FIG. 1 configured as described above is not shown when the double-sided image forming mode for forming images on both sides of a sheet is selected and the image forming operation is started. A toner image is formed on one surface of the paper P by the image forming unit, and the toner image is conveyed to the fixing unit 17 in an unfixed state, and the toner image is fixed there.

The sheet P is conveyed to the reversing conveying path 19 by the branching claw 18 which is switched to the position shown by the phantom line in FIG. It is sent onto the double-sided tray 12 by the conveying force of the separation roller 13 and the separation roller 42. The paper P
Immediately after being fed onto the double-sided tray 12, the front, rear, left, and right positions are aligned by side fences and end fences 43 (not shown). Then, in the case of forming a double-sided image on a plurality of sheets, this series of operations is repeated.

In this way, when all of the designated number of sheets are stacked on the double-sided tray 12, the bottom plate 15 feeds the paper P on the double-sided tray 12 in the direction opposite to the arrow A in FIG. The roller 13 is rotated to an ascending position indicated by an imaginary line. As a result, the sheets P are sequentially re-fed from the topmost sheet. Note that this re-feeding is performed while the paper P on the double-sided tray 12 is aligned in the front, rear, left, and right positions by the pair of side fences and the end fence 43, so that it is not skewed or is not fed. .

The rotation of the bottom plate 15 and the rotation of the feed roller 13 are performed by the same motor 22 as described with reference to FIG. 3, and the rotation of the bottom plate 15 is performed by the speed reduction mechanism 23. Is the feed roller 1
As described above, when 3 is rotated in the sheet re-feeding direction (second direction) indicated by the arrow B, the bottom plate 15 moves to the raised position later.

That is, the double-sided device 1 according to this embodiment.
Means that when the motor 22 rotates in the direction of arrow C in FIG. 3, the feed roller 13 rotates in the direction opposite to arrow B,
When all of the designated number of sheets have been stacked on the double-sided tray 12, this motor 22 rotates in the direction opposite to the arrow C to start the re-feeding operation. As a result, the drive gear 24 rotates clockwise in FIG. 3, and the first idle gear 25 meshing with the drive gear 24 rotates counterclockwise. Further, the rotational force is transmitted to the roller drive gear 38 via the second idle gear 26, and the feed roller 13 rotates in the direction of arrow B via the feed roller shaft 16 integrated with the roller drive gear 38.

A third idle gear 27 is also meshed with the second idle gear 26, and an input gear 28 having a cam 29 for rotating the bottom plate 15 is meshed with the third idle gear 27. Therefore, the input gear 28 simultaneously rotates in the clockwise direction in FIG.

The rotation speed of the input gear 28 is slower than the rotation speed of the roller drive gear 38 because the speed reduction ratio of the speed reduction mechanism 23 is increased by increasing the number of teeth of the input gear 28. Therefore, the input gear 28 rotates slowly with respect to the rotation of the roller drive gear 38, and the cam 29 rotates in the arrow E direction from the position shown in FIG. 4 at the rotation speed thereof.

Abutment portions 29a and 29b are formed on the outer periphery of the cam 29 at positions different from each other by 180 ° in phase, and when the cam 29 rotates in the arrow E direction, as shown in FIG. When the contact portion 29b contacts the stopper 45, further rotation of the cam 29 is restricted.

After that, the input gear 28 continues to rotate in the clockwise direction in FIG. 3, but the rotation of the input gear 28 idles at the portion of the clutch 30 mounted between the input gear 28 and the cam 29. 29 is stopped. In this way, when the cam 29 rotates to the position shown in FIG. 5, the pin 34 attached to the cam 29 becomes the position farthest from the bottom plate 15, so that the pressure spring 35 moves the pressure arm 36 in the arrow direction. Rotate in the F direction.

Therefore, the lever holding shaft 39 rotates in the same direction, and the pressure lever 37 fixed thereto rotates in the same direction, so that the pressure lever 37 causes the bottom plate 15 to rotate.
Is rotated to the ascending side, and the uppermost sheet stacked on the bottom plate 15 is moved to the ascending position shown by the phantom line in FIG. And
The movement of the bottom plate 15 to the raised position is delayed from the timing when the feed roller 13 starts rotating in the direction opposite to the arrow A in FIG.

When the cam 29 is rotated in the counterclockwise direction from the position shown in FIG. 5 to the position shown in FIG. 4, the pressure lever 37 rotates in the clockwise direction in FIG. Since it is biased by the weak spring, it returns to the position shown in the figure by the biasing force, and the bottom plate also returns to the position shown in the figure by its own weight.

By the way, in this double-sided device 1, a paper is pressed against the feed roller 13 as described in FIG.
It has been described above that the elastic guide 14 is provided for applying a conveying force to the paper by the rotation of the feed roller 13. The direction of the tip portion 14a of the elastic guide 14 changes in accordance with the rotation direction of the feed roller 13. When the tip portion 14a of the elastic guide 14 changes its direction, in the conventional double-sided device, it largely bends in the middle as described with reference to FIG. Therefore, when this bending operation is repeated, cracks Cr occur in the tip portion 4a of the elastic piece 4 as described in FIGS. 10 (a) and 10 (b), and the tip portion 4a is cut early from there. It was easy.

However, in this embodiment, as described with reference to FIG. 2, a plurality of grooves 20 parallel to the axis of the feed roller shaft 16 are formed on the outer peripheral surface of the feed roller 13 over the entire circumference, and the elastic guide 14 is formed. Since the tip portion 14a is fitted in the groove 20 and changes its direction following the rotation of the feed roller 13, the bending amount when the elastic guide 14 changes its direction is small.
The elastic guide 1
4 has excellent durability.

That is, as shown in FIG. 6, when the feed roller 13 changes its rotation direction from the arrow A to the arrow B, the tip end 14a of the elastic guide 14 contacts the outer peripheral surface of the feed roller 13. Therefore, as shown in the drawing, the direction of the tip portion 14a can be changed from leftward to rightward.
Of the feed roller 1 as it enters into the groove 20 and is bent under the same condition as the entire length is shortened by the depth of the groove 20.
The amount of bending is reduced by the depth of the groove 20 as compared with the case where the groove 20 is not provided in 3.

This also applies to the case where the feed roller 13 changes its rotation direction in the opposite direction (when the rotation direction is changed from the arrow B to the arrow A). By forming the groove 20 on the outer peripheral surface of the feed roller 13 in this manner, the amount of bending when changing the direction of the elastic guide 14 can be reduced, so that the elastic guide 14 can be prevented from being cut early and the elastic guide 14 can be prevented. The durable life of 14 can be extended.

The shape of the groove 20 formed on the outer peripheral surface of the feed roller 13 can be V-shaped or U-shaped, but may be any other shape. The depth of the groove 20 is equal to the depth of the feed roller 1 of the elastic guide 14.
3 is appropriately determined in consideration of the contact length with respect to 3 and its shape.

[0039]

As described above, according to the present invention, even if the direction of the tip of the elastic piece is repeatedly changed every time the feed roller changes the rotation direction, the elastic piece is difficult to be cut, which is excellent. Since it has durability, the elastic piece can reliably feed the paper with the image formed on one side to the double-sided tray for a long period of time.
The sheet can be re-fed without causing a jam.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a double-sided device according to the present invention together with a part of an image forming apparatus.

FIG. 2 is a perspective view showing a feed roller also provided in the double-sided device and an elastic guide whose tip portion is in contact with the feed roller.

FIG. 3 is a perspective view showing a mechanism for driving a feed roller and a bottom plate of the double-sided device of FIG.

FIG. 4 is a schematic view showing a state in which a cam for rotating the bottom plate is also in a rotation position when feeding a sheet to a double-sided tray.

FIG. 5 is a schematic view showing a state in which the cam is in a rotation position when the paper is sent out from the double-sided tray.

FIG. 6 is a schematic diagram for explaining a state in which each time the elastic guide changes its direction, the bending generated in the process is reduced by the action of the groove formed on the outer peripheral surface of the feed roller provided in the double-sided device of FIG. It is a figure.

FIG. 7 is a perspective view showing an example of a feed roller and an elastic guide that comes into contact with an outer peripheral surface of the feed roller in a conventional double-sided device.

FIG. 8 is a front view showing the orientation of the leading end portion of the elastic guide when the sheets are stacked and the orientation when the paper is re-fed by a virtual line and a solid line, respectively.

FIG. 9 is a schematic view showing a state in which the direction of the tip portion of the conventional double-sided device changes while the elastic guide largely bends when the rotation direction of the feed roller changes.

FIG. 10 is a schematic diagram showing step by step a process in which a tip is cracked and cut when the tip of the elastic guide is changed while the elastic guide is largely bent as shown in FIG.

[Explanation of symbols]

 1: Double-sided device 12: Double-sided tray 13: Feed roller 14: Elastic guide (elastic piece) 14a: Tip part 20: Groove

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location B65H 5/36 B65H 5/36 G03G 15/00 106 G03G 15/00 106

Claims (1)

[Claims] 1. A double-sided tray for accommodating a sheet having an image formed on one side, and a first sheet for feeding the sheet into the double-sided tray.
In a double-sided device provided with a feed roller rotatable in a direction of and a second direction for feeding the paper from the double-sided tray, and an elastic piece arranged so that a tip end portion abuts on an outer peripheral surface of the feed roller. A plurality of grooves parallel to the axis of the feed roller are formed on the outer peripheral surface of the feed roller, and the tip end of the elastic piece is fitted into the groove so that the direction changes in accordance with the rotation direction of the feed roller. A double-sided device characterized in that