JP3400538B2 - Document feeder for image forming apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document feeding apparatus attached to an image forming apparatus such as a copying machine, a facsimile machine or a printer, in which at least one turn portion is formed in a document conveying path.

[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. Reversing of the original in this ARDF is generally performed by a turn portion provided with a driving reverse roller. Considering the load on the original and the load on the drive system, the diameter of the reverse roller is as small as possible. It is preferable to take it large. 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, it is difficult to reduce the turn diameter because it is not possible to solve the problem of the load on the document and the load on the drive system by simply reducing the diameter of the reversing roller.

In view of the above-mentioned conventional circumstances, the present invention is a document feeder capable of reducing the load on the document and the load on the drive system at the time of reverse conveyance with a simple structure and reducing the diameter of the turn portion. Is intended to provide.

[0005]

In order to achieve the above object, the present invention provides a document feeding device of an image forming apparatus in which at least one turn portion is formed in a document feeding path, wherein the turn portion is consists of document guide members of the inner and outer circumferential sides, Ri rotatable der document guide member of the inner peripheral side in the circumferential direction of the turn portion, the document guide member of the inner peripheral side
Is attached so that it can come in and out of contact with the document guide member on the outer peripheral side.
The document guide member on the inner peripheral side is moved to the document guide member on the outer peripheral side.
Characterized by being elastically held at a position close to the door member
I am trying.

[0006]

Further, in order to achieve the above-mentioned object, the present invention is characterized in that the document guide member on the inner peripheral side is made of a material having elasticity.

Further, in order to achieve the above object, the present invention is characterized in that the document guide member on the inner peripheral side is composed of a plurality of roller-shaped ribs attached to a support shaft.

[0009]

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. The load does not increase even if the document guide member on the inner peripheral side is caught when passing through the sheet, and the diameter of the turn portion can be reduced.

[0010]

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, there is provided a reversal entrance drive section composed of a reversal drive roller 10 and an entrance driven roller 11, and the document guide member 1 on the outer peripheral side is provided subsequent to the entrance drive section.
There is provided a turn portion constituted by 2 and a guide roller 13 as a document guide member 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, the shaft 14 and the roller-shaped rib 15 of the guide roller 13 may be separate members, and the roller-shaped rib 15 may be rotatably attached to the shaft 14. The one formed integrally with the roller rib 15 is preferable. 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 the reversal exit drive constituted by the reversal drive roller 10 and the exit driven roller 19 is performed. It is returned to the conveyor belt mechanism 4 again via the section.

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 a predetermined position above and exposed to light, it is conveyed to the reversing / discharging mechanism 6 and advances along the conveying path in the reversing / discharging mechanism 6 by the reversing drive roller 10 and the inlet driven roller 11, and is turned by the guide roller 13. At this time, the switching claw 17 is switched to the position indicated by the chain line, so that the paper is discharged to the original paper discharge section 8 between the paper discharge rollers 18.

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. It is turned along the guide roller 13, discharged from the reverse path by the reverse driving roller 10 and the reverse outlet driven roller 19, and is conveyed to a predetermined position on the contact glass 3 by the conveyor belt mechanism 4 which rotates in reverse at the timing. , The back side is exposed. Then, 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 / ejecting mechanism 6, and particularly when it is double-sided, it is turned around the guide roller 13 for almost one turn. However, since the guide roller 13 rotates freely, even if the document is stiff. , Can be turned without increasing the load. Therefore, the allowance for reducing the turn diameter increases, and the turn diameter can be reduced.
FIG. 4 is a perspective view showing another embodiment of the present invention. In this embodiment, the bearing 20 is attached to the shaft 14 of the guide roller 13, and the bearing 20 is inside the elongated hole 21 formed in the side plate 16 of the ARDF 1. Is mounted so as to be slidable in the longitudinal direction. In this case, the longitudinal direction of the long hole 21 is a direction in which the guide member 12 on the outer peripheral side is brought into contact with and separated from the guide member 12 on the outer peripheral side at substantially the apex of the turn, that is, substantially the vertical direction of FIG. A guide roller spring 22 is provided as an elastic member that is pressed against one end. The guide roller spring 22 elastically holds the guide roller 13 at a position close to the document guide member 12 on the outer peripheral side.

In the ARDF 1 having such a structure, when the document is turned by the reversing / discharging mechanism 6, the guide roller 13 is freely rotated even if a load is applied to the guide roller 13 by the waist of the document, and the guide roller 13 is long. Since it is displaced along the hole 21 in the direction away from the guide member 12 on the outer peripheral side, the load can be reliably and significantly reduced. Therefore, the allowance for reducing the turn diameter is increased, and the turn diameter can be reduced.

FIG. 5 is an explanatory view showing still another embodiment of the present invention. In this embodiment, the guide roller 13 is made of a flexible material, and therefore the guide roller 13 itself is proper. It has elasticity.

In the ARDF 1 having such a structure, when the document is turned by the reversing / discharging mechanism 6, even if a load is applied to the guide roller 13 by the waist of the document, the guide roller 13 itself elastically displaces as shown in the figure and turns. The time load can be reduced reliably and significantly. Moreover, since the structure is simple, it can be provided at low cost.

[0020]

According to the first aspect of the invention, the document on the inner peripheral side is provided.
The guide member rotates freely, and the document guide on the outer peripheral side
Since it is displaced against the elasticity in the direction of approaching and separating from the member,
The diameter of the turn section can be reduced, and the original
Reliably and significantly reduce the load when passing through
be able to.

[0021]

According to the second aspect of the present invention, since the document guide member on the inner peripheral side is made of a material having elasticity, the load when the document passes through the turn portion can be reliably and significantly reduced. It is possible, and the configuration is simple and inexpensive.

According to the third aspect of the invention, since the document guide member on the inner peripheral side is formed by the roller rib, the conveyance resistance becomes smaller than that of the one formed by the surface, and the smooth document conveyance can be obtained.

[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.

FIG. 4 is a perspective view of a guide roller showing another embodiment of the present invention.

FIG. 5 is an explanatory view of a guide roller showing still another embodiment of the present invention.

[Explanation of symbols]

1 ARDF 6 Inversion and discharge mechanism 12 Outer peripheral side guide member 13 Guide rollers 14 Guide axis 15 Rolled ribs 21 long hole 22 Guide roller spring

Front page continuation (51) Int.Cl. ⁷ Identification code FI G03G 15/00 510 G03G 15/00 510 (72) Inventor Masahiro Minato 1-3-6 Nakamagome, Ota-ku, Tokyo Within Ricoh Company ( 56) References JP-A-1-236126 (JP, A) JP-A-60-258033 (JP, A) Actually opened 54-38043 (JP, U) Actually opened 5-95946 (JP, U) (58) ) Fields surveyed (Int.Cl. ⁷ , DB name) B65H 5/36 B65H 15/00 B65H 29/20 B65H 85/00 G03G 15/00

Claims (3)

(57) [Claims] 1. A document feeding device of an image forming apparatus, wherein at least one turn portion is formed in a document feeding path, wherein the turn portion is composed of an inner peripheral side and an outer peripheral side document guide member. circumferential side of the document guide member is Ri rotatable der in the circumferential direction of the turn portion, the document guide member of the inner peripheral side of front
It is attached to the document guide member on the outer peripheral side so that it can come in and out of contact with
The document guide member on the inner peripheral side is the document guide portion on the outer peripheral side.
Characterized by being elastically held at a position close to the material
Document feeder. 2. The document feeder of the image forming apparatus according to claim 1 , wherein the document guide member on the inner peripheral side is made of a material having elasticity. 3. The document feeder of the image forming apparatus according to claim 1 , wherein the document guide member on the inner peripheral side comprises a support shaft and a plurality of roller-shaped ribs attached to the support shaft. A document feeder which is characterized in that