JPH10139184A - Document feeding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a document feeding device wherein a feeding failure is reduced and the backside of a document is prevented from being stained during feeding. SOLUTION: A pickup belt 3 is provided by protruding an upper surface slightly upward from a document placing surface 1, the document placing surface 1 is inclined upward toward the downstream more than the pickup belt 3, a separation roller 5 is provided to be protruded slightly upward in the upper end part of its inclined surface 1a and thus a contact area of the document with the pickup belt 3 during secondary feeding is reduced and friction resistance is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a document feeder provided in an image forming apparatus or the like which feeds a document from the lowest order of a document bundle stacked on a document table.

[0002]

2. Description of the Related Art In a document feeder in an image forming apparatus which feeds documents starting from the lowest one stacked on a document mounting table, for example, as shown in FIG. 3, a document a is fed. The pick-up roller b and the feed roller d of the document separating section c are each supported at a height projecting several millimeters above the upper surface of the document table e.

[0003] Therefore, in order to reduce the transport load during the secondary paper feeding by the paper feeding and separating rollers f and g, a one-way clutch is provided inside the pickup roller b and the feed roller d, and the fed document a Thereby, both rollers b and d can be rotated. In FIG. 3, h is a reverse roller, i is a contact glass, j is a conveyor belt, m and n, q and r are a pair of discharge rollers, s and t are a pair of discharge rollers, and u is a pair of discharge rollers.
Is a discharge port, and the copied document a is circulated and discharged to the original position on the document table e.

[0004]

In the conventional document feeder as described above, since the contact area between the pickup roller b and the document a at the time of paper feeding is small, the paper feeding pressure is likely to be unstable, and the paper feeding failure is caused. Is easy to occur. In addition, since the paper feed pressure exerts a large effect locally, the back side of the document a tends to be stained. In other words, when the document surface is strongly pressed locally on the back surface of the document a, the toner or ink on the document surface may adhere to the back surface of the document a.

The present invention has been made in view of such circumstances,
It is an object of the present invention to provide a document feeder in which a feeding failure is reduced and a back stain of a document during feeding is reduced.

[0006]

According to the present invention, means for solving the above-mentioned problems are constituted as follows. That is, the pickup belt is provided with the upper surface projecting slightly above the document placing surface, and the document placing surface is inclined upward toward the downstream side from the pickup belt portion, and the upper end of the inclined surface is inclined. In this case, the separating roller is provided so as to protrude slightly upward to reduce the contact area of the original with the pickup belt at the time of secondary paper feeding, thereby reducing frictional resistance.

With the pickup belt, the contact area during document feeding can be increased, and feeding defects can be eliminated. In addition, since the local pressing force can be prevented from acting on the document, the occurrence of back contamination of the document can be prevented.

Since the separating roller is provided at a position higher than the pickup belt, when the document is pulled in the feeding direction during the secondary feeding, the contact area of the document with the pickup belt is reduced, and the frictional resistance is reduced. The need for a one-way clutch is eliminated.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a document feeder according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is an overall configuration diagram of a document feeder, and FIG. 2 is an enlarged view of a main part. In these drawings, reference numeral 1 denotes a document mounting table, 2 denotes a paper width regulating plate, 3 denotes a pickup belt, and the pickup belt 3 supplies a supply belt. The document placing table 1 is arranged with its leading end slightly inclined upward in the paper direction, and the document placing table 1 is inclined upward from the leading end of the pickup belt 3 toward the downstream side, and the upper end of the inclined surface 1a. The separating roller 5 is provided so as to protrude slightly upward, and a separating belt 6 is provided corresponding to the separating roller 5.
An original front end regulating member 4 is provided on the front surface of the separating belt 6.

Reference numeral 7 denotes a carry-in roller, 8 denotes a reversing roller that slides in contact with the carry-in roller 7 and rotates clockwise. A document carry-in path 9 is formed between the pickup belt 3 and the carry-in roller 7. A roller 10 slides on the reversing roller 8, and a document reversing path 12 is formed so as to surround the reversing roller 8 from the guide plate 11.

A contact glass 14 is stretched downstream of the carry-in roller 7 and the reversing roller 8, and a transport belt 13 is provided thereon. In addition, contact glass 1
An exposure scanning system 15 is provided directly below 4. 17
And 18 are a pair of discharge rollers, 19 is a discharge path, 20 and 21 are a pair of discharge rollers, and 22 is a discharge port.

As described above, by employing the pickup belt 3 for feeding the original, the contact area with the original D at the time of feeding can be widened. Paper defects can be eliminated, and a local pressing force can be prevented from acting on the document D, so that the occurrence of back contamination of the document D can also be prevented.

Since the separating roller 5 is provided at a position (step h) above the pickup belt 3, the secondary feeding of the document D is started by the carry-in roller 7 and the reversing roller 8. As shown in FIG. 2, the document D is slightly lifted by being pulled, so that the contact area with the pickup belt 3 is reduced, and the frictional resistance is reduced, so that the pickup belt 3 does not require a one-way clutch. The separating roller 5 has a built-in one-way clutch.

When a normal automatic circulation of the original feed is performed by the original feeder, the originals D stacked on the original placing table 1 are sent one by one from the original input passage 9 onto the contact glass 14 to the copy output passage. The document D is discharged to the uppermost position of the document D from the discharge port 22 by the pair of discharge rollers 20 and 21 via 19, so that copying can be performed again. In the course of such a document D feeding operation, the pickup belt 3
As described above, the paper feeding failure and the back stain of the document are eliminated by adopting the method described above.

[0015]

As described above, according to the document feeder of the present invention, the pickup belt is provided with the upper surface projecting slightly above the document placing surface, and the document placing surface is picked up by the pickup belt. The contact area of the document with the pickup belt at the time of secondary feeding is reduced by inclining upward toward the downstream side from the belt portion and providing a separating roller at the upper end of the inclined surface so as to protrude slightly upward. The contact area can be increased by the pickup belt at the time of paper feeding, so that poor feeding can be eliminated, and a local pressing force acts on the document. Can be avoided, so that it is possible to prevent the back side of the document from being stained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating an embodiment of a document feeder according to the present invention.

FIG. 2 is an enlarged view of the main part.

FIG. 3 is a configuration diagram illustrating an example of a conventional document feeder.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Original mounting table (original mounting surface), 1a ... Inclination surface, 3 ... Pickup belt, 5 ... Separation roller, D ... Original.

Claims (1)

[Claims] A pickup belt provided with an upper surface protruding slightly above the document placing surface, and the document placing surface being inclined upward toward the downstream side of the pickup belt portion; A separating roller is provided at an upper end portion of the document feeder so as to protrude slightly upward to reduce a contact area of the document with the pickup belt at the time of secondary feeding, thereby reducing frictional resistance. apparatus.