JPS5947295B2 - Automatic document feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic document feeder in a copying machine.

2. Description of the Related Art Various automatic document feeding apparatuses have already been proposed that automatically feed a document to be copied to a predetermined position on a document mounting table, thereby eliminating the need for opening and covering a document pressure plate and placing the document.

One such automatic document feeder uses a plurality of endless belts as a document conveying means.

An example of this apparatus will be described with reference to FIG. 1. Reference numeral 1 indicates a main body of the copying machine. A document mounting table 2 made of a transparent glass plate is arranged on the top surface of the copying machine main body 1.
A known copying mechanism (not shown) is provided below it. A pair of belt pulleys 3 and 4, each of which is rotatable, is arranged above the document table 2.

A plurality of pulleys 3 and 4 are mounted on support shafts 5 and 6 that extend in the width direction of the original document mounting tables 3 and 4, that is, in a direction perpendicular to each other in a horizontal plane with respect to the original feeding direction. An endless belt T whose surface facing the document table is painted white is stretched between the pulleys 3 and 4, and a tension pulley 8 abuts on this belt to apply appropriate tension. Further, the underbus portion of the endless belt T is adapted to substantially slide into contact with the upper surface of the document mounting table 2. A support shaft 6 of one belt pulley 4 is connected to an output shaft 10 of a drive motor 9, and is adapted to rotate the pulley 4 clockwise.

Belt T and guide plate 11 stretched around belt pulley 4
A document insertion port 12 is formed by the document insertion port 12. On the right side edge of the document platform 2, as shown in the figure, there is a device that can freely reciprocate between a protruding position that protrudes upward from the top surface of the document platform 2 and a lowered position that descends from the top surface of the document platform 2. A strike 7/13 for positioning the original is provided. Further, on the opposite side of the endless belt T from the document table 2, that is, on the inner peripheral surface of the belt, a belt presser plate 14 whose lower surface is painted white or the like is disposed.

This belt presser plate 14 is provided to suppress vibration of the belt 7 during document feeding to ensure stable document feeding, and to prevent illumination light from passing through a relatively thin document. In the automatic document feeder configured as described above, when a predetermined amount of document o is inserted from the document insertion slot 12,
A detection switch (not shown) detects this and starts the drive motor 9 to rotate the endless belt 7 clockwise.
Due to this rotation of the endless belt 7, the original o is fed to the left in the figure while sliding on the original placing table 2 due to the friction of the belt, and its leading edge is brought into contact with the stopper 13 in the protruding position. It stops when it collides with the doorstop type. On the other hand, the drive of the endless belt 7 is cut off approximately at the same time as the document stops. When the copying operation of the document 0 placed at a predetermined position is completed, the stopper 13 descends to the lowering position, and the endless belt 7 rotates again.
The document 0 is discharged from the discharge port 15 onto the document tray 16.

By the way, in a device that feeds documents using a plurality of endless belts as described above, the side edges of the document being fed (particularly the side edges parallel to the feeding direction) are curled upward and also diagonally. If the belt is moved, the side edge may enter the inner circumferential surface of the endless belt 7, causing a problem.

That is, as shown in FIG. 2, the side edge 0a is curled,
Moreover, when the obliquely traveling original 0 is ejected, the same side edge 0a is sandwiched between the inner circumferential surface 7a of the endless belt 7 and the outer circumferential surface of the belt strip 3, and the entire original advances in the direction of the arrow a. However, since the sandwiched side edge continues to follow the belt, the side edge 0a is damaged.

In FIG. 2, the document 0 shown by the chain line is shown before being sandwiched between the belt and the pulley, and the document 0 shown by the solid line is shown with the side edge 0a damaged by being caught between them. SUMMARY OF THE INVENTION An object of the present invention is to provide an automatic document feeding device that does not cause the document to be caught in the belt and pulleys even if the document curls toward the endless belt.

The present invention will be explained below with reference to an illustrated embodiment.

In FIG. 3, a stepped portion 17 for preventing document intrusion is fixed on the lower surface of the belt presser plate 14 in parallel with the document feeding direction and facing the inner peripheral surface of the endless belt 7. As shown in FIG.

This stepped portion 17 has approximately the same width as the endless belt 7. Furthermore, it is not necessary to provide this stepped portion 17 corresponding to all the endless belts, and it may be provided only to correspond to the endless belts to which the side edges of documents of various sizes to be fed will correspond. good. Furthermore, as shown in FIG. 4, if the ridgelines 17a and 17b of the stepped portion 17 and the corners A and B formed by the stepped portion 17 and the belt presser plate 14 are formed at acute angles, Intrusion of the original into the inner peripheral surface of the belt can be further prevented. As described above, when the belt presser plate facing the inner circumferential surface of the endless belt is provided with a stepped portion for preventing document intrusion, the side edge of the step is placed on the document mounting table as shown in document 0 shown in FIG. If the document is curled in the opposite direction, even if the document is fed diagonally,
The side edge intrudes onto the inner circumferential surface of the belt, causing the belt to slip 3
(See Figure 2) This prevents the problem of being pinched and damaged or jammed.

In addition, by providing the stepped portion for preventing document intrusion parallel to the document feeding direction, the stepped portion acts as a guide member for the side edge of the curled original, thereby preventing skewed feeding of the original. It disappears. Note that the document intrusion prevention stepped portion may be integrally formed with the belt pressing plate, or may be substantially integrally fixed to a separate member.

[Brief explanation of drawings]

Figure 1 is a side sectional view showing an example of an automatic document feeder;
The figure is a perspective view showing a state in which a skewed document is sandwiched between an endless belt and a belt belt, FIG. 3 is a front cross-sectional view showing only the essential parts of an embodiment of the present invention, and FIG. It is an enlarged front sectional view showing only a portion. 2...Document placement table, 7...Endless belt, 14...Belt press plate, 17...Document intrusion prevention step, 0... ...Manuscript.

Claims (1)

[Claims] 1. In an automatic document feeder that uses a plurality of endless belts to feed a document to be copied to a predetermined position on a document platform, a belt presser is provided on the opposite side of the document platform to the endless belt. An automatic document feeding device characterized in that a plate is provided with a stepped portion for preventing document intrusion, which projects in the document feeding direction and toward the belt side in correspondence with the width of the belt.