JPH11301869A - Sheet feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To providing a sheet feeder capable of ensuring sorting of sheets to be delivered to a separation part. SOLUTION: A sheet S located at the highest position among sheets stacked on a feeding tray 6 is delivered into a sheet supplier by an up-and-down movable delivering roller 22 and the sheet S delivered by the delivering roller 22 is separated from another sheet S to be fed by a separating roller pair 23. The separation of the sheet S is ensured by a sheet sorting member 24 arranged between the delivering roller pair 23 and the separating roller 22 and inclined to the downstream side in a sheet delivering direction and a delivering guide 25 contacting the end at the downstream side of the delivered sheet sorting member 24.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding apparatus for feeding sheets stacked on a sheet feeding tray into an apparatus main body in a separated state.

[0002]

2. Description of the Related Art Conventionally, in a sheet feeder represented by, for example, an automatic document feeder (ADF) of a copying machine, a stacked sheet on a feed tray is fed from a top by a feed roller, and the fed sheet is fed. Sheets are separated after being separated one by one by a sheet feeder and a separating member.

At this time, in order to prevent the sheets fed from the feed roller from being fed to the separating section in a bundle state, one sheet (or 2 sheets) is fed between the separating section and the feed outlet.
A sheet is provided in advance for separating the sheets.

[0004] Further, as this separating plate, those having a sheet contact surface formed of a high friction member or those having only a front end side having a high friction member are generally used.

[0005]

However, such a separating plate has a leading edge of the sheet due to the loaded state of the sheets stacked on the sheet feeding tray or sheet deformation (deformation such as curling of the leading end). I got stuck on the high friction part,
There has been a problem that the sheet is not sent or the sheet is damaged.

Further, a sheet positioned above a stacked sheet may be fed out to the separating section without abutting against the high friction portion of the separating plate, which may cause a jam at the separating section and a sheet stain. Had become.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a sheet feeding device capable of reliably handling a sheet and feeding the sheet to a separation unit.

[0008]

In order to achieve the above object, according to the first aspect of the present invention, a sheet feeding tray for stacking sheets and a sheet at the top of the sheets stacked on the sheet feeding tray are provided. A vertically movable movable feeding means for abutting and feeding, a separating means for separating and feeding each sheet fed from the feeding means, and a separating means disposed between the feeding means and the separating means. A sheet separating member having an inclined surface with which the leading end of the fed sheet comes into contact, and a feeding guide for guiding a sheet fed by the feeding means to a downstream end portion of the sheet separating member in a sheet feeding direction. The gist of the invention is that:

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a sheet feeding apparatus according to the present invention will be described with reference to the drawings as applied to an automatic document feeder of a copying machine.

In FIG. 4, reference numeral 1 denotes a copying machine main body, the overall view of which is omitted. Reference numeral 2 denotes a platen glass of the copying machine main body 1. Reference numeral 3 denotes a document projection arranged along the downstream edge of the platen glass 2 in the document conveying direction. The scale 4 is an automatic document feeder (hereinafter simply referred to as “ADF”) as an apparatus main body mounted on the platen glass 2.

The ADF 4 includes a paper feed tray 6 mounted on the cover 5 for stacking sheets (original documents), a supply unit 20 for feeding the sheets stacked on the paper feed tray 6 to the platen glass 2, A transport belt section 30 for transporting the downstream edge of the sheet supplied on the platen glass 2 in the transport direction until the edge abuts against the document abutment scale 3 and transporting the read sheet further downstream;
And a paper discharge unit 40 that conveys and discharges a sheet supplied from the printer onto a paper discharge tray 7 provided on the cover 5.

The paper feed tray 6 includes a tray 6a capable of stacking a plurality of sheets in a face-down state, and a tray 6a.
A plurality of sensor switches 6b, 6b for detecting the length of the sheets stacked on the tray 6 and a sensor function for detecting the sheet width at the same time as aligning the width by contacting both width edges of the sheets stacked on the tray 6a Both end guides 6c are provided.

As shown in FIG. 1, the supply section 20 includes a sheet detection sensor section 21 for detecting the sheets S stacked on the sheet feeding tray 6 and a sheet detection sensor section 21 for detecting the number of sheets S stacked on the sheet feeding tray 6. Feeding roller 22 as an ascending / descending feeding means for feeding the positioned sheet S into the automatic document feeder 4
A pair of separating rollers 23 as separating means for separating and feeding the sheet S fed from the feeding roller 22 from other sheets S, and a sheet separating device disposed between the feeding roller 22 and the separating roller pair 23. A member 24, a feeding guide 25 for guiding the sheet S fed by the feeding roller 22 to the downstream end of the sheet separating member 24, and a front end detection for detecting the front end of the sheet S separated and fed from the separation roller pair 23. A sensor 26, a registration roller pair 27 for aligning the front ends of the sheets S separated and fed from the separation roller pair 23, and a rear end detection sensor 28 for detecting the rear end of the sheet S registered by the registration roller pair 27. Have.

The sheet separating member 24 is provided so as to be inclined upward toward the downstream side in the feeding direction of the sheet S, whereby the leading ends of the plurality of sheets S set in the sheet feeding tray 6 are sequentially displaced stepwise. This is for improving the separability of the sheet S. Also, the sheet separating member 2
4, a material having a relatively high friction coefficient such as rubber is used. At this time, the sheet S is further separated by making the friction coefficient at the downstream end in the feeding direction higher than that at the upstream end in the feeding direction. The performance is improved. When rubber is used for the sheet separating member 24, the leading end of the sheet S is not damaged by the pressing load when the sheet S is set.
A mylar 29 having a low friction coefficient may be provided before the sheet separating member 24 (upstream side in the sheet conveying direction). The mylar 28 may be formed in a comb shape.

The feeding guide 25 has one end 25a as a free end and the other end 25b rotatably held on the shaft 22a of the feeding roller 22, whereby the one end 25a is moved by its own weight to the leading end (sheet S) of the sheet separating member 24. (At the downstream end in the conveying direction), and at the same time, is moved (rotated) by the pressure of the sheet S fed from the feed roller 22. Further, since the other end 25b of the feeding guide 25 is held by the shaft 22a, the other end 25b moves in conjunction with the vertical movement of the feeding roller 22 according to the stacked amount of the sheet S.

By the way, in the above embodiment, the feeding guide 2
5 is rotatably held on the shaft 22a of the feeding roller 22, but as shown in FIG. 2, the feeding guide 35 may be rotatably held on one roller shaft of the separation roller pair 23. At this time, it is preferable that the end of the feeding guide 35 on the side of the feeding roller 22 is inclined upward so that the sheet can be easily inserted. The other configuration in FIG. 2 is the same as that in FIG.

As shown in FIG. 3, one end is connected to a shaft 22a.
A first arm 45a pivotally supported on the first arm 45a;
A second arm 45c rotatably supported by the other end of the arm 45a via a shaft 45b to form a feeding guide 45;
The shaft 45 is placed on the upper surface of the uppermost sheet S by its own weight.
b, the leading end of the second arm 45c is brought into contact with the leading end of the sheet separating member 24 (the downstream end in the transport direction of the sheet S) by its own weight, and the next feeding to the sheet separating member 24 is performed. It is also possible to further improve the separating performance by making the sheet abutment at two places.

The transport belt section 30 includes an endless belt 31 and a plurality of drive rollers 32 for rotating the endless belt 31 in forward and reverse directions, and has a known configuration.

The paper discharge section 40 includes a paper discharge roller 41, a document detection sensor (also used as a switchback sensor) 42, a discharge roller (also used as a switchback roller) 43, and the like, and has a known configuration.

In the above configuration, when the sheets S are stacked on the sheet feed tray 6, the sheet detection sensor unit 21 detects this, and at the same time, the feeding roller 22 and the feeding guide according to the amount of the stacked sheets S. The other end 25b of 25 is displaced upward in the figure.

When the leading end of the bundle of sheets S abuts on the sheet separating member 24, the leading end is sequentially displaced stepwise due to the inclination setting, and at the same time, one end 25a of the feeding guide 25 is placed on the upper surface of the top sheet S. Abuts by its own weight.

When a start switch (not shown) is turned on in this state, the uppermost sheet S is fed into the sheet feeding device 4 by the rotation of the feed roller 22.

At this time, since one end 25a of the feeding guide 25 is in contact with the upper surface of the uppermost sheet S, the next sheet S is pressed by the sheet separating member 24 by the pressure caused by its own weight. In this state, the sheet S is prevented from being fed out together with the uppermost sheet S.

The uppermost sheet S separated from the other sheets S is fed toward the registration roller pair 27 by the separation roller pair 23, and the registration roller pair 27
After the registration, the sheet is conveyed toward the conveying belt section 30.

As described above, when the uppermost sheet S among the sheets S stacked on the sheet feeding tray 6 is fed into the sheet feeding device 4, the sheet separating member 24 and the feeding guide 25 cooperate with each other. Since the uppermost sheet S is separated from the next and subsequent sheets S, the separability of the sheets S is further improved.

[0026]

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of a main part of a sheet feeding apparatus according to the present invention.

FIG. 2 is an enlarged sectional view of a main part of a modified example.

FIG. 3 is an enlarged sectional view of a main part of another modified example.

FIG. 4 is a vertical sectional view of the sheet feeding device.

[Description of Signs] S: Sheet 4: Sheet feeder (apparatus main body) 22: Feeding roller (feeding means) 23: Separation roller pair (separating means) 24: Sheet separating member 25: Feeding guide

Claims (8)

[Claims] 1. A sheet feeding tray for stacking sheets, a vertically movable movable feeding means for abutting and feeding the uppermost sheet of the sheets stacked on the sheet feeding tray, and the sheet being fed from the feeding means. Separating means for separating and feeding the separated sheets one by one; a sheet separating member disposed between the feeding means and the separating means and having an inclined surface with which the leading end of the fed sheet abuts; A sheet feeding device for feeding a sheet fed by means to a downstream end of the sheet separating member in a sheet feeding direction. 2. The sheet feeding apparatus according to claim 1, wherein the inclined surface of the sheet separating member has a higher coefficient of friction at the downstream end in the feeding direction than at the upstream end in the feeding direction. . 3. The sheet feeding device according to claim 1, wherein one end of the feeding guide comes into contact with a downstream end of the separating member. 4. A sheet feeding apparatus according to claim 3, wherein one end of said feeding guide is movable by pressure of a sheet fed from said feeding means. 5. The sheet feeding device according to claim 4, wherein one end of the feeding guide comes into contact with a downstream end of the separating member by its own weight. 6. The apparatus according to claim 1, wherein at least the other end of the feeding guide moves in accordance with a stacked amount of sheets.
A sheet feeder according to claim 1. 7. The sheet feeding apparatus according to claim 6, wherein the other end of the feeding guide moves in conjunction with the vertical movement of the feeding means. 8. The sheet feeding device according to claim 6, wherein one end of the feeding guide is rotatable with respect to the other end.