JP2001106370A - Automatic document conveying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that a large number of documents are inserted in a nip point between a feed belt and a separation roller and the separation roller is corotated to be unseparable. SOLUTION: This automatic document conveying device has a paper feed means 7 disposed above a manuscript base 3 on which a document bundle P is placed and taking out the uppermost document of the document bundle P; and separation/feed means 9, 10 for separating every one sheet of the manuscript taken out and feed it. An inhibition member 31 contacted with a lower surface of the document taken out by the paper feed means 7 and restricting a movement of the document positioned at a bottom portion is provided between the paper feed means 7 and the separation/feed means 9, 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic document feeder provided in a copying machine, a facsimile machine, a scanner, and the like. The present invention relates to an improvement in an automatic document feeder that feeds documents separately.

[0002]

2. Description of the Related Art An automatic document feeder generally includes a paper feed section, a scan section, and a paper discharge section. Documents fed one by one from a paper feed section are read by a scan section. The document is discharged from the paper discharge unit, and then the next document is fed. In the case of a double-sided document, the document is inverted by the sheet discharging unit, scanned again by the scanning unit, and the back side is also read, and then discharged from the sheet discharging unit.

An example of such an automatic document feeder is shown in FIG.
Shown in FIG. 3 is a partial sectional side view schematically showing a sheet feeding unit and a scanning unit of the automatic document feeder 1 mounted on a copying machine. In this automatic document feeder, a document table on which a document bundle is placed is composed of a fixed document table 2 and a movable document table 3 which rotates around a fulcrum 3a (in the AB direction in the figure). (Not shown), the set feeler 4 is moved by the bundle of originals and the set sensor 5 is moved.
, The original set is detected. When the document set is detected, the movable document table 3 moves up and presses the upper surface of the document bundle against the pickup roller 7. The pickup roller 7 is supported so as to be rotatable in the CD direction in the figure, and the movement of the pickup roller 7 is detected by a lift detection sensor 8.

[0006] A document bundle is placed on the pickup roller 7.
Is stopped, the pickup roller 7 is driven, and the originals are sequentially taken out from the uppermost surface of the original bundle. The pickup roller 7 is an example of a sheet feeding unit according to the present invention. The taken-out document reaches separation / feeding means including a feeding belt 9 and a separation roller 10 (referred to as a reverse roller or the like). In this separation and feeding means, the feeding belt 9 has two support rollers.
It is wrapped around 9a, 9b and is rotationally driven by the drive support roller 9a. The support roller 9b is a driven roller. The feeding belt 9 is pressed against the separation roller 10 by contact pressure applying means (not shown), and the document is nipped between the feeding belt 9 and the separation roller 10 and sent out, and sent out to the pull-out roller 11.

[0005] A document is fed from a pull-out roller 11 through a document conveyance path to a registration roller 13 and a conveyance belt driving roller 16.
To the conveyor belt 17 driven by the
The document is guided upward, scanned by the scanner 19, and the image on the document surface is read. Here, when the pull-out sensor 12 detects the document, the pickup roller 7 retracts in the upward C direction, and the pull-out sensor 12 detects the leading edge of the document.
Measure the length by detecting the rear end. The size detection sensor 14 detects the width of the document, and the registration sensor 15 detects the length of the document fed by the registration roller 13 to determine the stop position of the document on the contact glass 18. The original scale 20 is provided on the contact glass 18 and presses the original against the original scale 20 to define a scan start position. When reading of one document is completed, the document is output to the paper output section.
(Not shown, not shown), the document is discharged to a paper discharge tray, the next document is fed, and reading, image formation, and copying of the document are sequentially performed.

In this manner, the originals are taken out from the original bundle and processed one by one. Here, the operation of the separation feeding means by the feeding belt 9 and the separation roller 10 will be described. If the pickup roller 7 always takes out only one document, this separating / feeding mechanism does not need to work. However, since the pickup roller 7 takes out two or three documents, It is necessary to separate them so that they are fed one by one. The separation roller 10 is driven via a torque limiter in a direction opposite to the moving direction of the feeding belt 9.
If one document is nipped between the feeding belt 9 and the separation roller, the separation roller 10 is pulled by the frictional force with the document fed by the feeding belt 9 and fed. The document rotates in the moving direction of the belt 9 but the document
If more than one sheet is nipped, the document on the separation roller 10 slides, the torque on the separation roller 10 is lost, and the document is rotated in the original driving direction, that is, in the direction opposite to the moving direction of the feeding belt 9, and the document on the bottom of the document bundle Pull back. Thus, even if a plurality of originals are sent, they are separated one by one before the nip point. Such a separate feeding means is disclosed in Japanese Patent Application Laid-Open No. 11-217126.
And JP-A-11-222326.

[0007]

By the way, in such a separation feeding mechanism, when the friction coefficient between the originals is large, or when about ten originals are accidentally caused at the nip point between the feeding belt and the separation roller. When the paper is fed, the contact pressure between the feeding belt and the separation roller is increased, and the torque applied to the separation roller is also large. Thus, there is a problem that the separation roller rotates and cannot be separated. The present invention provides an automatic document feeder that solves such a problem.

[0008]

According to a first aspect of the present invention, there is provided a sheet feeding means which is located above a platen on which a bundle of originals is placed and takes out the uppermost original of the bundle of originals, and An automatic document feeder having separate feeding means for separating and feeding one sheet at a time, between the paper feeding means and the separating and feeding means, contacting the lower surface of the document taken out by the paper feeding means. ,
A blocking member for restricting movement of the document at the bottom is provided. As a result, the document at the bottom of the plurality of documents taken out can be blocked before the nip point in advance, so that double feeding of the document can be reliably prevented.

[0009] Further, when the guide member is provided with a predetermined gap above the blocking member, double feeding can be prevented more reliably. A blocking member having an inclined surface rising in the document conveying direction and a plate-shaped blocking member extending in the document width direction;
When the guide member is two rib-shaped guide members that hang down on the document conveying surface outside the both ends in the document width direction of the plate-shaped blocking member, the apparatus is compact, simple, inexpensive, and close to the blocking member. Document can be prevented from jamming. The separating / feeding means includes a feeding belt held by a supporting roller and a separating roller in contact with the feeding belt, and a feeding belt supporting portion provided with a guide member has a more compact and rational configuration. When the guide members are flanges formed at both ends of the support roller of the feeding belt, the device is simple, compact, and easy to manufacture.

When the surface of the blocking member is made of a material having a large coefficient of friction such as rubber, the blocking effect is increased.
In addition, if the leading end width of the plate-shaped blocking member is formed to be narrower in the document conveying direction, the document can be prevented from being jammed.

According to a second aspect of the present invention, there is provided a sheet feeding means which is located above an original platen on which an original bundle is placed and takes out the uppermost original of the original bundle, a feed belt held by supporting rollers, and Separation feeding means for separating and feeding the picked-up documents one by one and feeding the picked-up documents one by one. A disc-shaped conveyance guide is provided in the section. This makes it possible to form a conveyance path for preventing the movement of the superimposed document with a compact and simple structure, and to prevent double feeding of the document.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings showing preferred embodiments of the present invention.

FIGS. 1A and 1B are views showing a separation feeding section of an embodiment of an automatic document feeder according to the present invention, and FIG. 1A is a schematic side view, 1 (b) is a view on arrow XX in FIG. 1 (a). FIGS. 2A and 2B are views showing a separation feeding section of another embodiment of the automatic document feeder according to the present invention.
2 is a schematic side view, and FIG. 2B is a partial top view of FIG. 2A.

First, the embodiment shown in FIGS. 1A and 1B will be described. The configuration of this automatic document feeder except for the blocking member and the guide member according to the present invention is the same as that of FIG.
Are substantially the same as those of the automatic document feeder described above, and those having the same functions are denoted by the same reference numerals and description thereof is omitted. In FIGS. 1 (a) and 1 (b), reference numeral 21 denotes a guide path that forms a document conveyance path, and reference numeral 22 denotes an apparatus frame at the distal end portion of the movable document table 3. This is the same as that shown in the conventional device (see FIG. 3).

Reference numeral 31 denotes a blocking member provided between the pickup roller 7 serving as a paper feeding means and a separation feeding means including a feeding belt 9 and a separation roller 10, and is taken out at the leading end of the conveyance path 21. Provided near the leading end of the original bundle P. The blocking member 31 is a plate-shaped blocking member that has an inclined surface 31a that rises in the document conveying direction, extends in the document width direction, and has a surface made of a rubber material 31b. Reference numerals 32 denote two rib-shaped guide members that hang down from above toward the document conveying surface at positions outside both ends of the plate-shaped blocking member 31 in the document width direction, that is, at positions separated from the ends of the plate-shaped blocking member 31. The plate-shaped blocking member 31 is attached with a predetermined gap between the plate-like blocking member 31 and a gap through which several documents pass. The tip of the rib-shaped guide member 32 is formed in a smooth curved shape (see FIG. 1A).

The method of attaching the guide member will be described with reference to FIG. 3. If the guide member is attached to a support shaft of support rollers 9a and 9b for supporting the feeding belt 9, a bracket 9c for supporting the support shaft, or the like. be able to. The specific structure is appropriately determined based on the shape and position of the blocking member, but it is preferable to attach the support member to the support roller, particularly to the support roller portion on the upstream side, from the viewpoint of making the apparatus compact. As shown in FIG. 2 (b), the width of the leading end (downstream side in the document transport direction) of the blocking member 31 is reduced in the document transport direction.

In the automatic document feeder having the above separating and feeding mechanism, as shown in FIG. 1A, even if a plurality of documents P are taken out from the pickup roller 7 (feeding means), it is prevented. The movement of the separation mechanism is suppressed by the member 31 before reaching the nip point, and the document is blocked. Therefore, there is no trouble at the nip point as described above, and double feeding of the document can be prevented. Further, since the document is sandwiched from above by the guide member 32, the document can be more effectively prevented. In the case of a blocking member having a plate-like inclined surface, the document at the bottom of the document bundle can be effectively blocked by a simple member. Can be blocked.

Further, in the case where the leading end width is narrowed and the rib-shaped guide member is disposed above the leading end width, the gap between the blocking member and the guide member is constant, so that the original is not jammed and the original is smoothly prevented. (See FIG. 1 (b)).

In the embodiment shown in FIGS. 1A and 1B, a plate-shaped guide member having a rib-shaped or smooth edge-shaped tip is described as the guide member, but the guide member is not limited to this. Instead, as in the embodiment shown in FIGS. 2A and 2B, the guide member 33 may be a guide member 33 including flanges provided on both side ends of the support roller 9b of the feed belt 9. Thus the support roller
By providing the guide member 33 (flange) on 9a, the device becomes simple and compact, and it is possible to make the device easy and inexpensive to apply to conventional models.

Here, in the present invention, many originals
(Document bundle) is not introduced to the nip point of the separation / feed mechanism,
Before the nip point, the movement of the document bundle is suppressed and blocked. The document is blocked by the blocking member alone or by the cooperation of the blocking member and the guide member. When the blocking member having
A tapered conveying path having a wedge-shaped cross section is formed between the guide member 33 and the guide member 33 (flange). Overlapping originals can be prevented in this tapered wedge-shaped conveyance path.

According to the second aspect of the invention, the same operation and effect as those of the first aspect of the invention can be obtained, the apparatus can be made simpler and more compact, and the application to the conventional apparatus becomes easier.

In the above description, an automatic document feeder applied to a copying machine has been described. However, the automatic document feeder of the present invention is not limited to a copying machine, but may be an image forming apparatus such as a facsimile or a scanner. Applicable to printers and the like.
Although the pickup roller has been mainly described as the paper feeding means, the paper feeding means is not limited to the roller type, and any paper feeding means such as another friction take-out means can be adopted. The present invention is not limited to a belt and a separation roller (reverse roller), but may employ any separation and feeding means such as a feeding roller.

[0023]

According to the first aspect of the present invention, a sheet feeding means which is located above an original platen on which a bundle of originals is placed and which takes out the uppermost original of the original bundle, and the extracted originals are separated one by one And a separating and feeding means for feeding the original document, the bottom of the document being in contact with the lower surface of the document taken out by the feeding means between the feeding means and the separating and feeding means. Is provided, a document at the bottom of a plurality of taken out documents can be blocked before the nip point in advance, and double feeding of documents can be reliably prevented.

Further, a guide member provided with a predetermined gap above the blocking member can more reliably prevent double feeding. Other effects are as described above.

According to a second aspect of the present invention, there is provided a sheet feeding means which is located above an original platen on which an original bundle is placed and takes out the uppermost original of the original bundle, a feed belt held by a support roller, and Separation feeding means for separating and feeding the picked-up documents one by one and feeding the picked-up documents one by one. Since a disc-shaped conveyance guide is provided in the section, a wedge-shaped conveyance path for preventing the movement of the superimposed document is formed with a compact and simple structure, and double feeding of the document can be prevented.

[Brief description of the drawings]

FIG. 1 is a view showing a separation and feeding unit of an embodiment of an automatic document feeder according to the present invention, wherein FIG. 1 (a) is a schematic side view, and FIG. It is a XX arrow line view of (a).

FIGS. 2A and 2B are diagrams showing a separation feeding unit of another embodiment of the automatic document feeder according to the present invention, wherein FIG. 2A is a schematic side view, and FIG. FIG. 2A is a partial top view of FIG.

FIG. 3 is a partial sectional side view schematically showing a sheet feeding unit and a scanning unit when the automatic document feeder 1 is mounted on a copying machine.

[Explanation of symbols]

 7 Pickup roller (feeding means) 9 Feeding belt (separating feeding means) 9a, 9b Supporting roller 10 Separating roller (separating feeding means) 31 Inhibiting member 31a Inclined surface 31b Rubber material 32 Guide member (rib-shaped guide member) 33 Guide member (flange)

Claims (8)

[Claims] 1. A document processing apparatus, comprising:
In an automatic document feeder having a sheet feeding means for taking out the uppermost original of the bundle of originals and a separating / feeding means for separating and feeding the taken out originals one by one, An automatic document feeder, wherein a blocking member is provided between the feeding means and in contact with the lower surface of the document taken out by the paper feeding means and restricts the movement of the bottom document. 2. The automatic document feeder according to claim 1, wherein a guide member is provided above the blocking member with a predetermined gap. 3. The plate-like blocking member having an inclined surface rising in the document conveying direction and extending in the document width direction, wherein the guide member is formed by the plate-like blocking member in the document width direction. 3. The automatic document feeder according to claim 2, wherein two rib-shaped guide members are provided on both sides of the document and hang down on the document transfer surface. 4. A feeding belt comprising a feeding belt held by a supporting roller and a separating roller in contact with the feeding belt, wherein the guide member is attached to the feeding belt supporting portion.
Or the automatic document feeder according to 3. 5. The automatic document feeder according to claim 4, wherein said guide members are flanges formed at both ends of a support roller of said feed belt. 6. The surface of the blocking member is made of a material having a high coefficient of friction, such as rubber.
Or the automatic document feeder according to 5. 7. The automatic document feeder according to claim 3, wherein the width of the leading end of the plate-like blocking member is narrowed in the document feed direction. 8. A document processing apparatus, comprising:
Separating / feeding means comprising a feeding belt for taking out the uppermost document of the document bundle, a feeding belt held by support rollers and a separating roller contacting the feeding belt, for separating and feeding the taken-out documents one by one Wherein a disc-shaped conveyance guide is provided at both end portions of the support roller on the upstream side of the document conveyance of the feed belt.