JPH0577945A - Paper feeder - Google Patents

Abstract

PURPOSE:To provide a paper feeder wherein stably preventing an oblique feed is realized with no influence by a mounting error or the like of each roller, relating to the paper feeder utilized for a copying machine and a printer or the like. CONSTITUTION:The first roller 4 brought into light press contact with paper to feed it out and the second roller 5 arranged in the downstream in a feed direction of this paper are provided and constituted so as to arrange the first roller 11 displaced from the running center of the paper at a feed speed slower than the second roller 5 and so as to arrange the second roller 5 on the running center of the paper by increasing paper conveying force larger than the first roller 4. By this constitution, the paper can be conveyed to run always along guide plates 7, 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device used in a copying machine or a printer.

[0002]

2. Description of the Related Art Conventionally, in a copying machine or the like, a large number of sheets are stored in a paper feeding cassette, the paper feeding cassette is inserted into the main body of the copying machine, and the paper feeding cassette in the main body of the copying machine is used to insert the paper into the paper feeding cassette. The paper is sent out one by one, enabling continuous copying. The sheet feeding device is configured by a sheet feeding roller and a double feeding preventing unit in order to feed the sheets in the sheet feeding cassette one by one.

A conventional sheet feeding device of a copying machine will be described below with reference to the drawings. FIG. 2 is a sectional view of a main part of a conventional paper feeding device, and FIG. 3 is a plan view of a main part of the conventional paper feeding device.
In FIGS. 2 and 3, reference numeral 11 is a copying machine main body, and 12 is a paper feed cassette for storing the paper 13. The first roller 14 is a first roller for sending the paper 13 from the paper feeding cassette 12 to the copying machine main body 11 by lightly pressing it against the paper 13 and rotating it clockwise, and 15 is a second roller in the same direction as the first roller 14. Rotate. Reference numeral 16 denotes a reverse rotation roller, which is pressed by the second roller 15 and is given a rotational force in the clockwise direction via a torque limiter (not shown). The second roller 15 and the reverse rotation roller 16 form a double feed prevention mechanism. First roller 1
4, the second roller 15, and the reverse rotation roller 16 are arranged on the running center line of the sheet. Here, the running center means the center line of the paper width with respect to the running direction. Reference numeral 17 is a first guide plate for guiding the side of the paper stored in the paper feed cassette 12 in the traveling direction, and 18 is a second guide plate, which is arranged on the opposite side of the first guide plate 17 with the paper 13 interposed therebetween. It has a pressing member 19 for pressing the paper 13 toward the first guide plate 17.

The movement of each part when the paper is fed out by this conventional paper feeder will be described. The first roller 14 is shown in FIG.
At the same time, the second roller 15 rotates in the clockwise direction to feed the uppermost sheet in the cassette, and at the same time, the second roller 15 also rotates at substantially the same feed speed. At this time, if there is a double feed of the sheets, the reverse feed roller prevents the double feed and only the uppermost one sheet is fed to the copying machine main body.

[0005]

However, in the above-mentioned conventional sheet feeding device, the feed speeds of the first roller and the second roller are almost the same, and both rollers are arranged on the running center of the sheet. When the paper is shaken in either the arrow A direction or the B direction in FIG. 3 due to the mounting error such as the inclination of the first and second rollers, especially when the paper is shaken in the B direction, the second guide plate has a clearance with the side surface of the paper. Because there is no regulation, there are
The paper remains slanted as indicated by the broken line (13a)
There was a problem that it was sent (skew occurs).

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned conventional problems and to provide a sheet feeding device which is stable and is prevented from being skewed by the mounting error of each roller.

[0007]

In order to solve the above-mentioned problems and to achieve the object, a paper feeding apparatus of the present invention comprises a first guide plate for guiding one side surface in a traveling direction of stored paper, and A second guide plate having a pressing member on the other side surface of the sheet for pressing the sheet toward the first guide plate, and a first sheet that is sent out by lightly pressing the stored sheet and rotating the sheet. A roller and a second roller arranged on the downstream side in the paper feeding direction, the first roller has a lower feeding speed than the second roller, and the second guide plate side with the traveling center of the paper removed. The second roller is disposed closer to the center of travel of the sheet, and has a stronger sheet conveying force than the first roller.

[0008]

With this structure, when the sheet is fed by the first roller and is conveyed by the second roller, the feeding speed of the first roller is lower than the feeding speed of the second roller, so that the first roller exerts a braking effect on the sheet. At the same time, the effect of pressing the sheet toward the first guide plate side is obtained, and the sheet always travels along the first guide plate side, so that skew can be stably prevented.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view of the essential portions of the paper feeding device of the present invention. Since the configuration of the sheet feeding device of the present invention shown in a cross-sectional view is the same as the configuration of the conventional sheet feeding device shown in FIG. 3, detailed description thereof will be omitted. In FIG. 1, 1 is a copying machine main body and 2
Holds paper 3 in a paper feed cassette. 4 is lightly pressed against the paper 3 and is rotated to rotate the paper feed cassette 2
The first rollers 5 that send the paper 3 to the main body 1 of the copying machine are the second rollers and rotate in the same direction as the first roller 4. A reverse rotation roller 6 is pressed against the second roller 5 and is given a rotational force in a clockwise direction via a torque limiter (not shown). The second roller 5 and the reverse rotation roller 6 form a double feed prevention mechanism. Reference numeral 7 is a first guide plate for guiding the side of the paper stored in the paper feed cassette 2 in the traveling direction, and 8 is a second guide plate which is arranged on the opposite side of the first guide plate 7 with the paper 3 interposed therebetween. It has a pressing member 9 for pressing the paper 3 toward the first guide plate 7. The first roller 4 is arranged closer to the second guide plate side than the center of paper running.
The reverse rotation roller 6 is arranged on the running center line of the paper,
Further, the second roller 5 is set to have a stronger sheet carrying force than the first roller 4.

Next, the movement of each part when the paper is fed by this paper feeding device will be described. At the same time as the first roller 4 rotates in the clockwise direction to feed the uppermost sheet in the cassette, the second roller 5 rotates at a feeding speed faster than that of the first roller 4. At this time, if there is a double feed of the sheets, the reverse feed roller prevents the double feed as in the conventional apparatus, and only the uppermost one sheet is fed to the main body of the copying machine. As described above, since the sheet feeding speed and the sheet conveying force are larger in the second roller 5 than in the first roller 4, the sheet 3 is sandwiched between the first roller 4 and the second roller 5 at the same time. The first roller 4 exerts a braking effect on the sheet 3 as it is conveyed. Further, since the first roller 4 is provided near the side of the second guide plate with the traveling center of the sheet removed, the conveying force of the second roller 5 gives the sheet 3 a moment in the direction of arrow A. That is, since the sheet 3 is conveyed while being always pressed against the first guide plate 7 (3a), a stable skew feeding prevention effect is always obtained.

As a result of experiments, it was found that the most stable skew preventing effect can be obtained when the first roller is arranged at a position where the end surface 4a of the first roller substantially coincides with the running center. It was In this embodiment, the case where the paper is fed from the paper feed cassette has been described, but it goes without saying that the same configuration can be applied to a paper feed device profitable to the main body of a device such as a copying machine, for example, a manual paper feed tray section. Further, in this embodiment, the roller of the double feed prevention mechanism is used as the second roller, but it is also possible to use the second roller exclusively for the skew feeding prevention.

[0013]

As described above in detail, according to the present invention, the first guide plate for guiding one side surface in the traveling direction of the stored sheets and the sheet on the other side surface side of the first sheet A second guide plate having a pressing member that presses toward the guide plate;
A first roller that sends out the sheet by lightly pressing the stored sheet and rotating the sheet and a second roller that is arranged on the downstream side in the sheet feeding direction are provided, and the first roller is the second roller. The feeding speed is slower, the center of travel of the sheet is removed, and the second roller is disposed closer to the side of the second guide plate. The second roller is disposed on the center of travel of the sheet. With the configuration in which the conveying force is strengthened, the paper can always be made to travel along the first guide plate, and a stable skew feeding prevention effect can be realized.

[Brief description of drawings]

FIG. 1 is a plan view of a main part of a sheet feeding device according to an embodiment of the present invention.

FIG. 2 is a sectional view of a main part of a conventional paper feeding device.

FIG. 3 is a plan view of a main part of a conventional paper feeding device.

[Explanation of symbols]

 4 1st roller 5 2nd roller 7 1st guide plate 8 2nd guide plate 9 Pressing member

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location // B65H 9/10 A 8922-3F

Claims (1)

[Claims] 1. A first guide plate for guiding one side surface of a stored sheet in a traveling direction, and a pressing member on the other side surface side of the sheet for pressing the sheet toward the first guide plate. A second guide plate, a first roller that slightly presses the stored paper to rotate the paper, and rotates the first paper; and a second roller that is disposed downstream of the paper in the paper delivery direction.
A roller, the first roller has a slower feed speed than the second roller, and is disposed closer to the second guide plate side than the traveling center of the sheet, and the second roller is the traveling center of the sheet. A sheet feeding device, which is arranged above and configured to have a stronger sheet conveying force than the first roller.