JPH07315658A - Document feeding device of image forming device - Google Patents

Abstract

PURPOSE:To provide a document feeding device which can surely obtain document conveyance force necessary for a turn portion even if a diameter of the turn portion is reduced. CONSTITUTION:An inversion inlet drive section consisting of an inversion drive roller 10 with a comparatively large diameter and an inlet driven roller 11 with a small diameter is provided at an inlet of an inversion/discharge mechanism 6, and an inversion outlet drive section consisting of the inversion drive roller 10 and an outlet driven roller 19 is provided at an outlet which is inverted in such a way that it nearly makes a round of a guide roller 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is provided with a turn portion for discharging an exposed original in the original feeding path, and the original reversing path for exposing both sides of the original can be switched at the turn. The present invention relates to an original feeding device attached to an image forming apparatus such as a formed copying machine, a facsimile, or a printer.

[0002]

2. Description of the Related Art In recent years, the number of double-sided originals has increased due to the multi-functionality of copying machines and the saving of paper resources. Therefore, in order to easily obtain a double-sided copy from a double-sided original in a conventional document feeding apparatus, an apparatus having a reversing function capable of automatically exposing both sides of the double-sided original (hereinafter referred to as ARDF) has been proposed. It is general that the document is inverted and discharged in this ARDF after it is turned by a turn portion provided with a driving reversing roller. Therefore, in consideration of the load on the document and the load on the driving system, the reversing roller is considered. It is preferable to make the diameter of the reversing roller as large as possible. On the other hand, in image forming apparatuses such as copying machines, demands for downsizing have been increasing year by year. Therefore, it is desired to reduce the diameter of the reversing roller, which is the turn diameter of ARDF.

[0003]

[Problems to be Solved by the Invention] However, ARD
In order to reduce the turn diameter of F, it is necessary to solve the problems of the load on the document and the load on the drive system. In particular, since ARDF conveys a wide variety of originals,
It is necessary to reliably turn even a strong original, and as the speed of copying machines increases, it is necessary to secure a driving force that allows the speed at the turn portion. Therefore, the conventional A
In the case of RDF, if the diameter of the reversing roller or the like is simply reduced, not only the problem of burden on the original document cannot be solved, but also the original document conveying force necessary for the turn portion cannot be obtained.

In view of the above-mentioned conventional circumstances, it is an object of the present invention to provide a document feeding device which can surely obtain the document feeding force required for the turn portion even if the diameter of the turn portion is reduced.

[0005]

In order to achieve the above object, the present invention is provided with a turn portion for discharging an exposed original document in a document conveying path, and both sides of the original document are exposed in the turn portion. In the document feeding device of the image forming apparatus in which the document reversing path for switching is formed, the document feeding means for applying a document feeding force to the entrance of the turn portion and the exit of the document reversing path is provided. It has a feature.

Further, in order to achieve the above-mentioned object, the present invention has a driving rotary member having a common document conveying means provided at the entrance of the turn portion and the exit of the document reversing path, and driven by the driving rotary member. It is characterized by comprising an inlet side driven rotating body and an outlet side driven rotating body.

[0007]

According to the above construction, the turn portion is composed of the inner and outer circumference side document guide members, and the inner circumference side document guide member is rotatable in the circumferential direction of the turn portion. Since the conveying force is applied in front of the turn section and the conveying force is also applied at the reversing exit, the original can be pulled out from the exit of the turn section, and the original conveyance in the turn section can be stabilized together with the conveying force of the entrance.

[0008]

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

FIG. 1 is an overall schematic view showing an ARDF according to the present invention. In FIG. 1, the ARDF indicated by reference numeral 1 is mounted on the main body 2 of the copying machine so as to be openable and closable on the contact glass 3 via a hinge (not shown). The ARDF 1 includes a conveyor belt mechanism 4 having a conveyor belt having a size that covers the contact glass 3, a document feeding mechanism 5 arranged on one side of the conveyor belt mechanism 4, which is the left side of the drawing in this example. It has a reversing / discharging mechanism 6 arranged on the right side of the drawing which is the other side of the conveyor belt mechanism 4. Further, a document table 7 for setting documents to be fed is provided at a position above the center of the ARDF 1, and a document discharge section 8 for stacking discharged documents is provided below the document table 7. In addition,
Since the conveyor belt mechanism 4 and the document feeding mechanism 5 are not the subject matter of the present invention, detailed description thereof will be omitted.

The reversing / discharging mechanism 6 of the ARDF 1 includes
As shown in FIGS. 1 and 2, a reversal entrance drive unit, which is composed of a reversal drive roller 10 having a relatively large diameter and an entrance driven roller 11 having a small diameter, is provided at the entrance as a document conveying means. Document guide member 1 on the outer peripheral side following the section
There is provided a turn portion constituted by 2 and the guide roller 13 on the inner peripheral side. As shown in FIG. 3, the guide roller 13 has a plurality of roller ribs 15 attached to a shaft 14 parallel to the shaft of the reversing drive roller 10. In this case, in the guide roller 13, the shaft 14 and the roller-shaped rib 15 may be separate members, and the roller-shaped rib 15 may be rotatably attached to the shaft 14, but the guide roller 13 is a mold.
4 and the roller rib 15 are preferably integrally formed.
If the guide roller 13 is formed by molding, there is no fear of a large load, so that the guide roller 13 can be attached to the side plate 16 without a bearing. Further, since the guide roller 13 is composed of the roller rib 15 having a relatively narrow width, the conveyance resistance becomes smaller than that of the one formed by the surface, and the smooth document conveyance can be obtained.

The reversing / discharging mechanism 6 is provided with a switching claw 17 following the turn portion having the above-described structure. When the switching claw 17 is switched to the position shown by the chain line in FIG. 2 by a solenoid (not shown), the document is discharged. The paper is ejected to the original ejection portion 8 by the paper roller pair 18. Further, when the switching claw 17 is switched to the position shown by the solid line in FIG. 2, the document is reversed so as to go around the guide roller 13 substantially once, and is constituted by the reversing drive roller 10 as the document conveying means and the exit driven roller 19. It is returned to the conveyor belt mechanism 4 again via the reversing outlet driving unit.

When the ARDF1 thus constructed is operated,
In the case of one-sided copying, the original fed by the original feeding mechanism 5 is transferred to the contact glass 3 by the conveyor belt mechanism 4.
After being stopped at the upper predetermined position and exposed, the document is conveyed to the reversing / discharging mechanism 6, and the document is first provided with a conveyance force sufficient to push the turn portion by the reversing drive roller 10 and the entrance driven roller 11. That is, the reverse driving roller 10
The entrance driven roller 11 applies a conveying force to the original while not turning the small-diameter turn portion of the original, but the original in front of the original is nearly flat, so that the original is sufficiently conveyed. Then, the document advances along the conveyance path in the reversing / discharging mechanism 6 and is turned by the guide roller 13, and at this time, the switching claw 1
Since 7 is switched to the position indicated by the chain line, the paper is ejected by the paper ejection roller 18 to the document ejection section 8. Therefore,
The document is fed by the reversing drive roller 10 and the entrance driven roller 11 so as to have sufficient conveying force to push through the turn portion, and then the leading end of the document is pinched by the paper discharge roller 18, the leading end side and the trailing end side of the document. Thus, even a turn portion having a small diameter due to the carrying force is provided with a carrying force sufficient to pass through it.

In the case of double-sided copying, the document feeding mechanism 5
First, the original fed by is first conveyed as it is on the contact glass 3 by the conveying belt mechanism 4 and guided to the conveying path in the reversing / discharging mechanism 6, and the switching claw 17 is switched to the position indicated by the solid line. When the document is turned along the guide roller 13 and the original becomes nearly flat, the reversing drive roller 10 and the reversing outlet driven roller 19 give a conveying force. Then, the original is discharged from the reverse path,
Conveyor belt mechanism 4 that rotates in reverse at the same timing
It is carried to a predetermined position on the contact glass 3 and the back surface is exposed. After that, the surface is exposed again after being reversed by the reversing / discharging mechanism 6, and is discharged to the document discharging section 31 through the reversing / discharging mechanism 6 as in the case of one-sided copying.

Thus, the document is turned by the reversing / discharging mechanism 6, and particularly when it is double-sided, it is turned around the guide roller 13 for one round, but the document is turned at the entrance of the reversing / discharging mechanism 6 by the reversing drive roller 10 and the inlet driven roller. Since the conveying force is given by 11 and the conveying force is given by the reversing drive roller 10 and the reversing outlet driven roller 19 at the outlet of the reversing / discharging mechanism 6, the conveying force necessary for the turn can be surely obtained. That is, if the document is fed by the reversing drive roller 10 and the inlet driven roller 11 with a sufficient conveying force to push through the turn portion and is reversed, the leading edge of the document is sandwiched between the reversing driving roller 10 and the reversing outlet driven roller 19. Since the document is pulled out from the exit of the turn section, the conveying force required for the turn can be reliably obtained. In addition, the guide roller 13 of the turn portion rotates freely, which increases the allowance for reducing the turn diameter.

The document transporting means on the entrance side and the exit side of the reversing / discharging mechanism 6 may be driven separately, but the reversing drive roller 10 is used on both the entrance side and the exit side as in this embodiment. This is extremely advantageous in terms of space saving and cost saving.

[0016]

According to the first aspect of the invention, since the document feeding means for applying a document feeding force to the entrance of the turn portion and the exit of the document reversing path are provided, respectively, before the turn portion where the feeding resistance is applied. Since the carrying force is applied and the carrying force is also applied at the reversing exit, the original can be pulled out from the exit of the turn section, and the original feeding of the turn section can be stabilized in combination with the carrying force of the entrance.

According to the second aspect of the present invention, the driving rotary member having the common document conveying means provided at the entrance of the turn portion and the exit of the document reversing path, and the inlet side driven rotation driven by the driving rotary member. Since it is composed of a body and an outlet-side driven rotator, one driving rotator can be used for both the entrance and exit document conveying means, and the structure is simple and can be provided at low cost.

[Brief description of drawings]

FIG. 1 is an overall schematic diagram showing an ARDF according to the present invention.

FIG. 2 is an enlarged view of the ARDF inversion / ejection mechanism.

FIG. 3 is a perspective view of the reversing / discharging mechanism.

[Explanation of symbols]

 1 ARDF 6 Reversing / Discharging Mechanism 10 Reversing Driving Roller 11 Reversing Entrance Followed Roller 13 Guide Roller 17 Switching Claw 19 Reversing Exit Followed Roller

Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication location G03G 15/00 510 (72) Inventor Masahiro Minato 1-3-6 Nakamagome, Ota-ku, Tokyo Within Ricoh Co., Ltd.

Claims (2)

[Claims] 1. An image forming apparatus in which a turn portion for discharging an exposed original is formed in an original conveying path, and an original inversion path for exposing both sides of the original is switchably formed on the turn portion. 2. The document feeding device according to claim 1, further comprising document feeding means for applying a feeding force to the document at the entrance of the turn portion and the exit of the document reversing path. 2. The document feeding device of the image forming apparatus according to claim 1, wherein the document feeding means provided at the entrance of the turn portion and the exit of the document reversing path have a common driving rotator, and the driving rotation. An original feeding device comprising an inlet side driven rotary body and an outlet side driven rotary body which are driven and rotated by a body.