JPS61238629A - Paper feeder provided with frictional separating device - Google Patents

Abstract

PURPOSE:To make a sheet conveyable accurately all the time while maintaining a degree of proper image quality, by forming a surface state of a sheet material admission part of a sheet material separating member into the specified roughness. CONSTITUTION:When surface roughness on a paper admission tip end of a holder for a sepalating member is set to a range of 6S-30S, stabilized paper feedability in a sheet material is securable. In addition, when a step difference between the holder part and the sheet material is set to a range of 0.1-0.25mm and a paper admission tip end form of the holder part is obliquely cut at 20 deg.-30 deg. from a through paper surface, a catch of the sheet material and contact between a roller and the holder part before a sheet comes into contact with the roller are brought to nothing and, what is more, stable paper feedability is securable without being affected by a sheet material tip end state.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a paper feeding device including a frictional separation means, and more particularly to a paper feeding device used in an image forming apparatus such as a copying machine.

[Conventional technology]

When automatically feeding sheet materials such as transfer materials, (1) A cassette loaded and stored with transfer materials of a predetermined size is installed in the copying machine, and one sheet is fed by a feeding means such as a feeding roller in the copying machine. (2) a loading table feeding method in which transfer materials placed directly on a loading table inside a copying machine are fed one by one by a feeding means; In particular, with the latter method, you only need to place dozens of sheets of transfer material directly onto the loading table, so there is no need for the trouble of attaching and removing cassettes as with the cassette feeding method, and you can easily replenish the transfer material when supplying the transfer material. There are advantages that can be achieved.

In the conventional loading platform feeding system, the transfer material separation member 2 is always pressed against the paper feed roller 1 with a constant pressure in the axial direction of the paper feed roller. The uppermost sheet is separated from other transfer sheets by the cooperation of the paper feed roller 1 and the transfer material separation sheet 3 of the transfer material separation member 2, which is pressed against the paper feed roller 1 by a spring 4. It has become.

In the transfer material separation member having the above structure, a friction member such as a rubber foam, rubber with cork, or a rubber plate is attached as the transfer material separation sheet 3 to the holder 5 made of resin (or metal may be used).

If the surface of the tip of the transfer material separation member is mirror-finished, dozens of sheets will come into contact with the transfer material separation sheet at the same time during paper feeding, resulting in transfer material separation being pressed by a spring against the paper feed roller. Since the member is pressed down by the sheet material, the paper feeding roller and the transfer material separation sheet cannot fully cooperate with each other, resulting in simultaneous feeding of multiple sheets called double feeding. Moreover, if the tip surface is rough, it has the disadvantage that the sheet material gets caught.

This drawback has a problem in that it affects the feeding of the sheet material.

[Purpose of the invention]

SUMMARY OF THE INVENTION The present invention eliminates the drawbacks of the prior art and aims to provide a paper feeding device that can always accurately feed sheet materials.

〔Example〕

The present invention will be explained below based on the illustrated embodiments.

FIG. 1 is a configuration diagram of a transfer material separating member showing an embodiment of the present invention.

It has been found that the relationship between the holder part of the transfer material separation member and the transfer material separation sheet can be solved by providing a step between the two.

If the level difference is too small, the sheet material will get caught, and if it is too large, the paper feed roller will come into contact with a portion of the holder before the transfer material separation sheet and the paper feed roller come into contact. Therefore, the difference in level to avoid both defects is 0.1 to 0.25 mm.
It is better to The shape of the paper entry end of a portion of the holder that achieves stable paper feeding performance without being affected by the state of the leading edge of the sheet material may be cut at an angle of 20'' to 30'' from the paper passing surface.

The surface roughness of the front end of the holder may be 6S to 30S to obtain stable sheet feeding performance.

The above was found out through experiments. Furthermore, Figure 1' (a
), the height relationship is A>B>C, and A is the highest.

〔Effect of the invention〕

Since the paper feeding device according to the present invention has the above-described configuration, it is possible to always accurately convey sheet materials and has the effect of obtaining appropriate image quality.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a transfer material separation member according to the present invention, and FIG. 2 is a layout diagram of a paper feed roller and a transfer material separation member. l-111 paper feed roller 2-111 transfer material separation member 3--1 transfer material separation sheet 4-1--pressing spring 5-111 holder

Claims (1)

[Scope of Claims] A paper feeding device comprising a paper feeding means and a sheet material separation member that contacts the outer peripheral surface of the paper feeding means and prevents simultaneous feeding of a plurality of copy sheets pulled out from a sheet stacking table. In this case, the surface condition of the sheet material entry part of the sheet material separating member is 6S~
A paper feeding device characterized by being 30S.