JPS61291340A - Automatic original feeder - Google Patents

Abstract

PURPOSE:To deliver a stack of originals piece by piece in an accurate manner even to such one that is curled upward, by setting up a separation belt to be tilted with an angle of less than the specified one with a delivery belt. CONSTITUTION:Adding pressure of W due to a weight plate, stacked originals 21 are delivered to the left by a paper feed roller 22, and an original at a lowermost position is conveyed to the left by a delivery belt 25, while the original situated more upper than the original at the lowermost position works so as to be put back to a right upper part by a separation belt 28. Hereat, force F for restoring the original by the separation belt 28 works rather in a horizontal direction than to be a right angle with the separation belt 28 by frictional force between the separation belt and each original 22. Therefore, component force F1 keeping the original is small but another component force F2 for pushing back the original grows larger. That is to say, when a tilt angle theta' is in a range of more than 60 deg. and an original tip end comes into contact with a rectilinear running part 28a of the separation belt 28, these stacked originals are delivered piece by piece in an accurate manner.

Description

DETAILED DESCRIPTION OF THE INVENTION (AJ Industrial Field of Application)
It relates to an automatic document feeder that automatically feeds a large number of stacked documents, and more specifically, a device that automatically separates and feeds documents set on a document tray one by one, starting from the bottom. Related to automatic feeding device.

(B) Conventional technology In general, image forming apparatuses use a feeding system that automatically separates and feeds originals stacked on an original platen 1 one by one, starting from the bottom, as shown in FIG. The document fed from the feeding device 2 is conveyed with the document side down to a predetermined position on the glass surface of the image forming device main body 3, and then stopped. Copying is performed here, and then the document is The document is conveyed to the left by the conveyance device 4, and at the left end, the document is reversed upward and stacked on the document tray 5 with the document surface facing up. Conventional automatic document feeding devices include one using rollers as shown in FIG. 5, or one using a belt as shown in FIG. 6.

In an automatic document feeder using rollers, as shown in FIG. The clockwise rotation transports it further to the left. This delivery roller 12 is made of a material having a large J@friction coefficient.

A separation roller 13 is disposed facing the delivery roller 12, and this separation roller 13 rotates in the opposite direction to the delivery roller 12, and is made of a material with a smaller coefficient of friction than the delivery roller 12, so that the document can be separated. It is designed to transport only one sheet to the left. A document regulating plate 14 is disposed in front of these rollers 12 and 13 facing each other, and a gap of about 1 to 2 spaces is provided between the document regulating plate 14 and the stacking table 15, so that the stacked documents cannot be The original document 410 is sent out one by one, and the leading edge of the sent original document is prevented from being turned up by the separation roller 13. The document regulating plate 14 is arranged on the mounting table 15 so as to be inclined by an angle θ, and prevents curled documents from flying out. Note that the original 10 is subjected to a pressure of W by a weight plate (not shown).

FIG. 6 shows an automatic document feeder using a belt, in which the document 10 on the stacking table 15 is sent to the left by the paper feed roller 11, and the conveyor belt 16 is driven counterclockwise. Separation belt 17 driven counterclockwise
Accordingly, only one document is conveyed to the left. Also in the automatic document feeder using this belt), the document regulating plate 14 is located in front of the belts 16 and 17.
Similar to the original regulating plate 14 shown in FIG. 5, the document regulating plate 14 is provided with a gap of about 1 to 2 degrees between it and the loading table 15, and is inclined at an angle θ.

←→ Problem to be Solved by the Invention Incidentally, if the inclination angle θ of the document regulating plate 14 in the automatic document feeder as described above is small, the leading edge of the document will curl upward. Therefore, it is desirable to increase the inclination angle θ for curled documents. However, when the inclination angle θ of B is increased, the following problem occurs. That is, in FIG. 7, if the reaction force of the force acting on the document regulating plate is F, then the component force F pushing the document downward is F.

-F, inθ, so if the inclination angle θ is increased, F
, becomes larger, which makes it easier to cause so-called double feeding, in which documents are sent out in duplicate. On the other hand, if the inclination angle θ is made small, documents curled upward will not be able to enter easily, which will impede paper feeding.

(b) Means for Solving the Problems The present invention aims to solve the above-mentioned problems, and is an automatic document feeder that feeds documents stacked on a stacking table one by one from the bottom. The feeding device includes a sending belt that sends out the lowest document among the stacked documents, and a separation belt that is driven above the exit belt in a direction opposite to the original sending direction, and the separation belt is connected to the delivery belt. The separation belt is arranged so as to be inclined diagonally upward toward the loading table at an angle of less than a predetermined angle (for example, about 30 degrees), and is configured such that the leading edge of the document comes into contact with the linearly running portion of the separation belt. It is something to do.

00 Effect Based on the above configuration, the lowest document stacked on the stacking table is sent out by the delivery belt, but the separation belt placed above the delivery belt is driven in the opposite direction to the delivery belt. and acts to return the original.

Since the separation belt is arranged to be inclined at an angle less than a predetermined angle with respect to the delivery belt, the force with which the separation belt pushes the document downward is considerably smaller than the force with which it pushes the document back.

(f) Example Embodiments of the present invention will be described below with reference to the drawings.

1 to 3 show an embodiment of the present invention,
The original 21 stacked on the original loading table 20 is moved to the paper feed roller 2.
2 sends it to the left.

A delivery belt 25 and a separation belt 28 are arranged on the left side of the document loading table 209. The delivery belt 25 is stretched between the delivery rollers 23 and 24, and is driven counterclockwise. The delivery belt 25 is made of a material with a large coefficient of friction, and transports the lowest document to the left. On the other hand, the separation belt 28 is stretched between the separation rollers 26 and 27, and is driven counterclockwise. The separation belt 28 is made of a material with a lower coefficient of friction than the delivery belt 25, and functions to return the document sent by the delivery belt 25.

The delivery belt 25 and the separation belt 28 are arranged alternately as shown in FIG. 2, and the lower end of the separation roller 26 is arranged slightly below the upper side of the delivery belt 25. The lower side of the separation belt 28 is arranged to extend toward the upper right at an angle α with respect to the upper side of the delivery belt 25. Therefore, the tip of the raw material 91121 comes into contact with the straight running portion 28a below the separation belt 28.

The distance between the document guide 29 and the stacking table 20 is arranged to be slightly wider than the maximum number of sheets that can be loaded. It is arranged above and to the right of the intersection of the separation bell 1- and the separation bell 1-.

The stacked original FMs 21 are subjected to a pressure W by a weight plate (not shown), and are sent out to the left by the paper feed roller 22, and the lowest document is conveyed to the left by the delivery bell 1-25. The documents located above the lowest document are returned to the upper right by the separation belt 28.

Here, the force F to return the document by the separation belt 28 is perpendicular to the separation belt 28 due to the vibration force between the separation belt 28 and the document 21 as shown in FIG. It acts in one direction. Therefore, the force F to hold the original
, is small, and the component force F2 that pushes back the original (becomes much larger).

In other words, when using a document regulating plate in the conventional example, if the inclination angle θ of the regulating plate is increased, the force for holding down the document increases, making double feeding more likely. The inclination angle θ' of the separation belt 28 with respect to the delivery belt 25 corresponds to the inclination angle θ of the plate.
It can be seen that this does not occur even if (θ' = 90° - α) is made considerably large. Especially for documents that curl upwards,
By tilting θ' to nearly 90° p14, good results were obtained in which each sheet was reliably fed out.

In other words, the inclination angle θ' is in the range of 60 degrees (when the angle α between the lower side of the separation belt 28 and the upper side of the delivery belt 25 is in the range of 30 degrees or less), and the leading edge of the document is separated. When the document comes into contact with the linear running portion 28a of the belt 28, the documents are reliably sent out one by one.

In addition, in this embodiment, the material of the exit belt 25 is as follows:
Although it is made of urethane rubber as a base and coated with a material having a high coefficient of friction to form a multilayer structure, it is of course possible to use other materials.

(G) As described in detail, according to the present invention, the delivery belt and the separation belt are arranged to be inclined at an angle of less than a predetermined angle, and the leading edge of the document is placed on the straight running portion of the separation belt. Because of this contact, it is possible to reliably feed out the original one sheet at a time even if the original is curled upward, and it is also possible to reliably prevent double feeding.

[Brief explanation of drawings]

FIG. 1 is a side view showing the main parts of the automatic document feeder of the present invention, FIG. 2 is a plan view of the sending belt and separation belt, FIG. 3 is a partially enlarged view of FIG. 1, and FIG. 4 is a conventional document feeder. Example schematic diagram, 5th
6 to 6 are side sectional views showing the main parts of a conventional automatic document feeder, and FIG. 7 is a partially enlarged view of FIG. 5. 20... Loading platform, 25... Delivery belt,
28-Separation belt, 28a/straight running part, 21/
...Manuscript.

Claims (3)

[Claims] (1) In an automatic document feeder that feeds originals stacked on a stacking table one by one from the bottom, there is a feeding belt that feeds out the lowest document among the stacked originals, and a feeding belt that feeds out the originals above the feeding belt. a separation belt that is driven in the opposite direction, the separation belt is arranged obliquely upward toward the loading platform at an angle of less than a predetermined angle with respect to the delivery belt, and a linear running portion of the separation belt is provided. An automatic document feeder characterized in that the document feeder is configured such that the leading edge of the document comes into contact with the document. (2) Claim 1 in which the predetermined angle is 30 degrees
The automatic document feeder described in Section 1. (3) The automatic document feeding device according to claim 1, wherein the delivery belt is made of a material having a higher coefficient of friction than the separation belt.