JPH11255393A - Automatic document feeding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a document discharged from being entangled in the rotation of a paper discharging roller when the discharging roller is rotated reversely. SOLUTION: One end of an entangling preventive sheet 14 made of a PET material is secured to the upper edge of an discharging hole 13 while the other end is located in a position lower than the nipping part of a paper discharging roller 9 and pressure roller 10 and near the lower edge of the discharging hole 13. Each document fed by the discharging roller 9 is discharging onto an discharging tray 12 while it is heaving the entangling preventive sheet 14. When the document on the tray 12 has increased and the uppermost document is going to move toward the discharging roller 9, the other end of the entangling preventive sheet 14 abuts on the trailing edge of the uppermost document and exerts a press.

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 applied to a copying machine, a scanner, a facsimile machine and the like.

[0002]

2. Description of the Related Art FIG. 4 is an explanatory view showing an example of the configuration of a main part of an automatic document feeder.
Is a pressure plate provided above the pickup roller 1 and urged to rotate downward, 3 is a guide cover, 4 is a contact glass, 5 is a separation roller, and 6 is a feed contacting the separation roller 5. 7, a registration roller; 7, a registration pressure roller that comes into contact with the registration roller 7 while applying pressure; 9, a discharge roller; 10, an impeller for kicking out the original; A paper discharge pressure roller 11 which comes into contact with a pressure on the paper is provided on a conveyance path from the registration roller 7 to the paper discharge roller 9, and a white pressure plate serving as a white reference, and 12 is a paper discharge roller by the paper discharge roller 9. A discharge tray 13 on which the stacked originals are stacked is a discharge port provided at a portion of the guide cover 3 which faces the nip portion between the discharge roller 9 and the discharge pressure roller 10.

An original set on the apparatus main body is a pressing plate 2
The pickup roller 1
Is conveyed from the lower document to the feed roller 6 side. At this time, when a plurality of sheets are conveyed, they are separated one by one by the separation roller 5 and the feed roller 6,
The sheet is conveyed to the registration roller 7 side. Then, the original is conveyed toward the contact glass 4 by the registration roller 7 and the registration pressure roller 8, and moves on the contact glass 4. Further, the leading end of the document that has passed over the contact glass 4 is flipped up by the impeller of the discharge pressure roller 10, separated from the contact glass 4, and formed in a nip portion between the discharge roller 9 and the discharge pressure roller 10. The paper is then sent through a discharge port 13 to a paper discharge tray 12 provided outside.

As a conventional technique of this kind, there is an image forming apparatus described in Japanese Patent Application Laid-Open No. Hei 5-139605. According to this publication, in an image forming apparatus for discharging a transfer material on which an image has been formed onto a document pressing plate, a pressing plate for holding the discharged transfer material is provided, and the pressing plate is increased with an increase in the opening angle of the document pressing plate. It describes a configuration in which a holding pressure adjusting means is provided.

[0005]

However, in the automatic document feeder shown in FIG. 4, when there are a large number of discharged documents staying in the discharge tray 12, as shown in FIG. The discharged original becomes easier to move to the discharge roller 9 side, and when the discharge roller 9 is reversely rotated at the time of initialization or the like, the uppermost discharged original is caught by the rotation of the discharge roller 9 and runs backward. There is a possibility that.

[0006] The present invention solves such problems,
An object of the present invention is to provide an automatic document feeder that prevents a discharged document from being caught by the rotation of the discharge roller when the discharge roller is rotated in reverse.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a transport roller for transporting a set of documents one by one, and a discharge roller for discharging the document transported by the transport roller to the outside. In the automatic document feeder provided with a discharge tray for stacking the discharged documents, a pushing member for pressing a rear end portion of the documents stacked on the discharge tray is provided at a document discharge port. It is characterized by.
With such a configuration, in the documents stacked on the paper discharge tray, the rear end of the document to be moved to the paper discharge roller side is pressed by the pressing member, so that the rear end of the document is ejected by the paper discharge roller. It is prevented from entering the nip with the paper pressure roller.

The present invention is characterized in that the pushing member is a flexible sheet member. Further, the sheet member is made of a PET material. According to such a configuration, when the document is discharged from the paper discharge port, the sheet member is bent by the stiffness of the document, and it is possible to prevent the transportability of the document from being deteriorated. In addition, after the document is discharged, the rear end of the document to be moved to the discharge roller side is pressed.

Further, according to the present invention, an impeller for kicking out a document is provided on one of the discharge roller and a discharge pressure roller abutting on the discharge roller, and a portion of the sheet member near the impeller is provided. Is extended, and the extended portion is configured to abut on the document that has been moved to the discharge roller side on the discharge tray. With such a configuration, the portion that is likely to cause the ejected document to be caught is the impeller. Therefore, by pressing down the document near the impeller, the document can be prevented from running backward, and the portion that comes into contact with the ejected document can be prevented. Therefore, it is possible to prevent the document transportability from being reduced.

[0010]

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

FIG. 1 is an explanatory view showing a main part of an apparatus according to a first embodiment of the present invention. Reference numeral 14 denotes an entrainment prevention sheet. The same members as those in the prior art shown in FIG. 4 are denoted by the same reference numerals, and detailed description is omitted.

The entrainment prevention sheet 14 is made of PET (poly)
a flexible member made of ethylene terephthalate) material, one end of which is fixed to the upper edge of the discharge port 13 and the other end of which is a nip portion between the discharge roller 9 and the discharge pressure roller 10 It is located below and near the lower edge of the outlet 13. The central portion of the roll-up prevention sheet 14 is bent at a shallow angle, and the other end of the roll-up prevention sheet 14 is inclined downward toward the discharge tray 12.

When the document is discharged, the document sent from the discharge roller 9 is discharged onto the discharge tray 12 while pushing up the wrap prevention sheet 14. Here, since the stacking surface of the paper discharge tray 12 is an upward slope, the rear end of the document discharged onto the paper discharge tray 12 is moved by its own weight and comes into contact with the rear surface side of the paper discharge tray 12. Become like Thereafter, when the number of originals staying on the paper output tray 12 increases and the uppermost original attempts to move toward the paper output roller 9, the wrap-around prevention sheet 14 The other end comes into contact with and presses, and the entry of the document into the paper discharge roller 9 is regulated.

According to the apparatus of the first embodiment configured as described above, when the number of originals staying on the paper output tray 12 increases, the rear end portion of the original that is to be moved to the paper output roller 9 side , The other end of the sheet 14 comes into contact with and presses the upper end of the sheet, thereby restricting the upward movement of the rear end of the document.
As a result, when the paper discharge roller 9 is reversely rotated at the time of initialization or the like, the trailing end of the uppermost document is caught by the rotation of the paper discharge roller 9 and the document can be prevented from running backward.
In addition, since the entanglement prevention sheet 14 is made of a PET material, the sheet resistance is small, and the sheet is appropriately elastically deformed, so that it is possible to prevent a decrease in transportability when discharging the document.

FIG. 2 is a plan view showing a main part of the apparatus according to a second embodiment of the present invention, and FIG. 3 is a side view of FIG.
Denotes impellers provided on both sides of the paper ejection pressure roller 10. The same members as those in the prior art shown in FIG. 4 and the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and detailed description is omitted.

In the second embodiment, the other end of the roll-up prevention sheet 14 in the first embodiment is formed in a concave shape. That is, extending portions 14a, 14a are provided on both sides of the discharge pressure roller 10 in the entanglement prevention sheet 14 so as not to contact the impeller 10a, and the tips of the extending portions 14a, 14a It is configured to contact and press the rear end of the document to be moved to the roller 9 side.

According to the device of the second embodiment configured as described above, the extended portions 14a, 14a have high flexibility,
The leading edge of the document from the paper discharge roller 9 is the wrap prevention sheet 1.
4 is ejected so as to collide with the original 4
Since it comes into contact with the portions a and 14a, the force that the document receives from the wrap-around prevention sheet 14 can be minimized as much as possible, and it is possible to reliably prevent a decrease in transportability when discharging the document. it can. In addition, the document being entangled, which is a problem to be solved in the present invention, largely depends on the impeller, and entanglement hardly occurs unless it is entangled in this portion. Therefore, by providing the extending portions 14a, 14a not in the entire area of the discharge roller 9 but in the portion of the impeller 10a, it is possible to prevent the lowering of the document transportability and to minimize the movement to the discharge roller 9 side. By pressing the upper document, it is possible to prevent the document from entering the paper discharge roller 9 and, as a result, to prevent the document from being entangled due to the reverse rotation of the paper discharge roller 9.

[0018]

According to the present invention as described above, since the rear end portion of the originals stacked on the paper output tray is pressed by the pushing member, the originals on the paper output tray are discharged from the paper output roller side. As a result, it is possible to prevent the document from being entangled when the paper discharge roller rotates in the reverse direction.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a main part of an apparatus according to a first embodiment of the present invention.

FIG. 2 is a plan view showing a main configuration of an apparatus according to a second embodiment of the present invention.

FIG. 3 is a side view of FIG. 2;

FIG. 4 is an explanatory diagram illustrating an example of a main configuration of the automatic document feeder.

FIG. 5 is an explanatory diagram showing a state in which the trailing end of a discharged document is entangled by a discharge roller

[Explanation of symbols]

 9 Discharge Roller 10 Discharge Pressure Roller 10a Impeller 12 Discharge Tray 13 Discharge Port 14 Entrapment Prevention Sheet 14a Extension

Claims (4)

[Claims] A transport roller for transporting the set documents one by one; a discharge roller for discharging the documents transported by the transport rollers to the outside; and a discharge tray for stacking the discharged documents. In the automatic document feeder,
An automatic document feeder, wherein a pushing member is provided at a document ejection opening to press a rear end of the documents stacked on the sheet ejection tray. 2. The automatic document feeder according to claim 1, wherein said pushing member is a flexible sheet member. 3. The automatic document feeder according to claim 2, wherein said sheet member is made of a PET material. 4. An impeller for kicking out a document is provided on one of the discharge roller and a discharge pressure roller abutting on the discharge roller, and a portion of the sheet member near the impeller extends. The automatic document feeder according to claim 2, wherein the extended portion is configured to contact the document moved to the discharge roller on the discharge tray. 5.