JP2693633B2 - Paper feeder - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a sheet feeding device provided in, for example, a copying machine or a printer, and more specifically, it is suitable for feeding thick sheets such as postcards. Sheet feeding device.

(Prior Art) An image forming apparatus such as a copying machine or a printer is equipped with a sheet feeding device for feeding a sheet to a developing section or a printing section. FIG. 3A shows an example of a paper feeding device that can automatically feed thick paper such as postcards. The flat plate-shaped hopper 32 disposed in the casing 31 is rotatably supported so that its side portion in the sheet feeding direction comes into contact with and separates from the bottom plate 31a of the casing 31. A paper feed roller 34 is disposed facing the paper feed side of the hopper 32. The side of the hopper 32 on the paper feed side is urged toward the paper feed roller 34 by a push spring 33.

A separating rib 35 is arranged in the paper feeding direction of the hopper 32. The separating ribs 35 are arranged on each side portion in the width direction orthogonal to the sheet feeding direction. Each of the separating ribs 35 has a triangular cross section, and a sharpened tip portion is close to the sheet feeding roller 34. Hopper 32 of the separating rib 35
The side surface on the side is substantially orthogonal to the paper feeding direction, and the tip end portion close to the paper feed roller 34 is in an inclined state in which it is slightly distant in the paper feed direction toward the tip end side.

In such a sheet feeding device, the hopper is attached to the sheet feeding roller 34.
The uppermost paper on the top 32 is pressed. Then, by rotating the paper feed roller 34, the uppermost sheet is conveyed toward the separation rib 35. At this time, when the lowermost sheet is conveyed together with the uppermost sheet, the lower sheet abuts the separating rib 35 and moves downward along the side surface of the separating rib 35 on the hopper 32 side. However, the sheet cannot get over the separating rib 35.

However, when the tip of the uppermost sheet placed on the hopper 32 is curled downward, the tip of the sheet abuts the separating rib 35 and cannot cross the separating rib 35. There is a risk.

Therefore, as shown in FIG. 3B, the auxiliary sheet 37 is attached to the surface of the separating rib 35 on the hopper 32 side. The tip of the auxiliary sheet 37 is separated from the separating rib 35, and the sheet conveyed by the paper feed roller 34 normally passes over the tip of the separating rib 35 from the tip of the auxiliary sheet 37 and is conveyed. To be done. Even if the leading edge of the sheet is curled downward, the leading edge is prevented from moving downward by the auxiliary sheet 37.

Further, in FIG. 4A, the separation blocks 40 are provided on the sides of the hopper 32 in the sheet feeding direction, and on the respective side portions in the width direction orthogonal to the sheet feeding direction. The separation block
40 has a block main body portion 41 located on the paper feed direction side of the hopper 32, and a guide portion 42 extending to the hopper 32 side on the side portion of the block main body portion 41 on the paper feed roller 34 side. The separation rib 43 faces the guide portion 42 via the slit 46. The side surface of the separating rib 43 on the hopper 32 side is substantially orthogonal to the paper feeding direction. The sheet conveyed by the sheet feeding roller 34 passes through the slit 46 of the separation block 40, and the sheet that is double-fed with the sheet is prevented from being conveyed by the separation rib 43.

Even in such a sheet feeding device, if the leading end of the sheet conveyed by the sheet feeding roller 34 is curled downward, the sheet may not be conveyed due to contact with the separation rib 43. is there. For this reason, as shown in FIG. 4B, an auxiliary sheet 47 is attached to the side surface of the block main body 41 on the hopper 32 side. Paper feed roller 34 of the auxiliary sheet 37
The side tip portion is in a state of being slightly spaced from the side surface of the separating rib 43 on the hopper 32 side. When the paper with the leading end on the paper feed side curled downward is conveyed by the paper feed roller 34, the leading end of the paper is fed to the auxiliary sheet 47.
It is prevented from moving downward by the leading end of the sheet, guided by the leading end of the auxiliary sheet 47, and passed through the slit 46.

(Problems to be Solved by the Invention) In the sheet feeding device as shown in FIGS. 3B and 4B, the auxiliary sheet 37 for guiding the sheet curled downward at the leading end in the sheet feeding direction or It is necessary to accurately attach 47 to the predetermined position. If the auxiliary sheet 37 or 47 is displaced from the predetermined position, the sheet cannot be reliably fed. For this reason, the auxiliary sheet 37 or 47 must be accurately attached to a predetermined position, which lowers the efficiency of assembling the sheet feeding device.

The present invention solves such a problem, and an object of the present invention is to provide a sheet feeding device which is easy to assemble and can perform a stable sheet feeding operation.

(Means for Solving the Problem) A sheet feeding device of the present invention is provided with a flat plate-shaped hopper on which a large number of sheets are placed, and a side portion on the sheet feeding direction side of the hopper so as to face each other. A paper feed roller, an urging means for urging the side of the paper feed side of the hopper toward the paper feed roller to bring the paper on the hopper into contact with the paper feed roller, and a paper feed roller of the hopper. The first separating member and the second separating member are arranged laterally on the paper side and are displaced in the paper feeding direction, and the surfaces on the paper side are both formed in a downward slope shape. A plurality of second separating members are provided both in the width direction orthogonal to the sheet conveying direction, and each of them has a sheet separating unit whose front end is close to the peripheral surface of the sheet feeding roller. By doing so, the above object is achieved.

Further, the sheet feeding device of the present invention includes a flat plate-shaped hopper on which a large number of sheets are placed, and a sheet feeding roller arranged to face a side portion of the hopper on the side of the sheet feeding direction. , In order to bring the paper of the hopper into contact with the paper feed roller,
Urging means for urging the side of the paper feed side of the hopper toward the paper feed roller, and the side of the paper feed side of the hopper,
A sheet separating means disposed downstream of the sheet feeding roller in the sheet conveying direction conveyed by the sheet feeding roller, wherein the sheet separating means are displaced from each other in the sheet feeding direction. In addition, a plurality of first separating members and second separating members, both of which are provided in the width direction orthogonal to the conveying direction of the paper and whose paper-side surfaces are both inclined downwardly, the first separating member and the second separating member. The above-mentioned object is achieved by a guide member disposed above the member and facing each other with a gap allowing the passage of the sheet.

(Operation) The operation of the present invention will be specifically described below with reference to FIG. 1 as an example.

That is, a large number of thick sheets 50 such as postcards placed on the hopper 12 are urged toward the sheet feeding roller 14 by the urging force of the push spring 13 (urging means). The uppermost sheet 50 is pressed against the sheet feeding roller 14. Then, as the paper feed roller 14 rotates in the direction of arrow A, the uppermost sheet 50 is conveyed together with the peripheral surface of the paper feed roller 14 due to the frictional force of the peripheral surface of the paper feed roller 14. At this time, the sheet 50 immediately below may be fed together with the sheet 50 on the uppermost side.
The tip of the inclined surface 15 of the first separating rib 15 (first separating member).
When it comes into contact with a, its transportation is blocked. Then, only the uppermost sheet 50 is conveyed by the frictional force of the peripheral surface of the sheet feeding roller 14.

At this time, even if two sheets of paper 50 are double-fed without being prevented from being double-fed by the inclined surface 15a of the first separating rib 15, both papers 50 are separated by the second separating rib 16 (second separating rib). Member) inclined surface 16a
By abutting against, the conveyance of the lower sheet is surely blocked.

Thus, the inclined surface 15a of the first separating rib 15 and the second
Since each of the inclined surfaces 16a of the separation rib 16 prevents double feeding of the paper 30, the inclined surfaces 15a and 16a can be set to a relatively gentle inclination with respect to the paper conveyance direction. As a result, even if the leading end of the uppermost sheet 50 on the sheet feeding side is curled to the side opposite to the sheet feeding roller 14, the sheet 50 still has the first separating rib 15 and the second separating rib 16. It is reliably transported without being blocked.

In addition, in the present invention, a plurality of the first separating ribs 15 and the second separating ribs 16 are both provided in the width direction orthogonal to the conveying direction of the sheet 30, and the tip end of each of them is on the peripheral surface of the sheet feeding roller 14. Since they are arranged close to each other, that is, opposed to each other with a slight gap, the tip portions of the first separating rib 15 and the second separating rib 16, especially between the tip portion of the second separating rib 16 and the peripheral surface of the sheet feeding roller 14. In, the conveyance force due to the frictional force acts on the sheet 30 at a plurality of positions in the width direction of the sheet 30.

For this reason, according to the present invention, the sheet 30 is conveyed by a conveyance force of a plurality of evenly divided portions, so that the sheet can be fed straight after being prevented from double feeding. As a result, the leading edge of the paper can be easily adjusted, and therefore, when the paper feeding device of the present invention is used as a paper feeding device of an image forming apparatus such as a copying machine, copy defects do not occur.

Further, a plurality of sheet separating means are provided, both of which are displaced from each other in the sheet feeding direction and in the width direction orthogonal to the sheet conveying direction, and the sheets on the sheet side are both formed in a downward slope. And a second separating member, a first separating member and a second
Even when the guide member is provided above the separating member and facing each other with a gap that allows the passage of the paper, the first separating member and the second separating member cooperate with the guide member to prevent the paper from passing. Double feed can be reliably prevented.

(Example) An example of the present invention will be described below.

FIG. 1 shows a schematic configuration diagram of a first embodiment of a paper feeding device of the present invention. The paper feeding device of this embodiment has a casing 11 mounted on the printer body and a flat hopper 12 arranged in the casing 11. When the casing 11 is mounted on the printer body, the bottom plate 11a is in an inclined state, and the side plate 11b on the paper feeding side is continuously provided at the lower end of the bottom plate 11a.
Becomes almost horizontal. The hopper 12 disposed in the casing 11 is in a state of being inclined in the same direction as the bottom plate 11a of the casing 11, and the side edge portion of the upper portion thereof is rotatably supported by the side plate of the casing 11 by the shaft portion 12a. Has been done. The lower side of the hopper 12 on the paper feeding side is the bottom plate 11 of the casing 11.
It is urged in a direction away from the bottom plate 11a by a push spring 13 interposed between the bottom plate 11a and a. A thick paper 50 such as a postcard is placed on the hopper 12.

Face the bottom of the hopper 12 on the paper feed side
14 are arranged. The paper feed roller 14 has a hopper
The sheet 50 placed on the sheet 12 is pressed against the sheet by the urging force of the push spring 13. Then, the paper feed roller 14 is indicated by an arrow A.
By rotating in the direction indicated by
Due to the frictional force on the peripheral surface, the uppermost sheet is fed.

First separation ribs 15 are provided below the paper feed roller 14 in the vicinity of the hopper 12 in the paper feed direction, on the side portions in the width direction orthogonal to the paper feed direction. The first separating rib 15 is a horizontal side plate of the casing 11.
It is mounted on 11b and has a triangular cross section that tapers toward the top. The first separating rib
Reference numeral 15 denotes an inclined surface in which the tip of the side surface on the hopper 12 side is inclined so as to gradually move away from the hopper 12 as it becomes the tip.
It is 15a. Then, the leading end of the paper fed by the paper feed roller 14 comes into contact with the inclined surface 15a.

The second separating ribs 16 are arranged side by side in the width direction in the sheet feeding direction of the first separating ribs 15. The second separating rib 16 also has a triangular cross-section similar to the first separating rib 15, and the tip of the side surface on the side of the hopper 12 is inclined so as to gradually move away from the hopper 12 as it becomes the tip. surface
It is 16.

In the sheet feeding device having such a configuration, for example, a large number of thick sheets 50 such as postcards placed on the hopper 12 are provided.
Is urged toward the paper feed roller 14 by the urging force of the push spring 13, and the uppermost sheet 50 is
It is pressed against 14. Then, the paper feed roller 14 is indicated by an arrow A.
By rotating in the direction, the uppermost sheet 50 is conveyed together with the peripheral surface of the paper feed roller 14 by the frictional force of the peripheral surface of the paper feed roller 14. At this time, the uppermost sheet 50 and the sheet 50 immediately below may be fed,
The leading edge of the paper 50 below the inclined surface 15 of the first separating rib 15
When it comes into contact with a, its transportation is blocked. Then, only the uppermost sheet 50 is conveyed by the frictional force of the peripheral surface of the sheet feeding roller 14.

At this time, even if two sheets of paper 50 are double-fed without the double feed being prevented by the inclined surface 15a of the first separation rib 15, both papers 50 have the same inclined surface 16a of the second separation rib 16. By abutting against, the conveyance of the lower sheet is surely blocked.

Thus, the inclined surface 15a of the first separating rib 15 and the second
Since each of the inclined surfaces 16a of the separation rib 16 prevents double feeding of the paper 30, the inclined surfaces 15a and 16a can be set to a relatively gentle inclination with respect to the paper conveyance direction. As a result, even if the leading edge of the uppermost sheet 50 on the sheet feeding side is curled to the side opposite to the sheet feeding roller 14, the sheet 50 still has the first separating rib 15 and the second sheet.
The separation ribs 16 ensure that the separation ribs 16 are conveyed without being obstructed.

FIG. 2A shows another embodiment of the paper feeding device of the present invention. In the paper feeding device, a separation block 20 is provided on each side of the hopper 12 in the width direction in the paper feeding direction. As shown in FIG. 2 (b), each separation block 20 is a block body portion facing the side of the hopper 12 on the paper feed side.
21 and a guide portion 22 extending from the upper surface of the block main body portion 21 toward the hopper 12 side. A pair of first separating ribs 23 and second separating ribs 24 are juxtaposed in the width direction on the upper portion of the block body 21. The separation ribs 23 and 24 are displaced in the sheet feeding direction, and the first separation rib 23 is located on the hopper 12 side. Each separating rib 23
Each of 24 and 24 has a triangular cross-section that is tapered toward the upper side, and each tip thereof is flat. The flat surfaces at the tips of the separating ribs 23 and 24 and the guide portion 22 are provided with slits 25 and 26 having appropriate gaps.

In such a sheet feeding device, the uppermost sheet 50 placed on the hopper 12 is pressed against the peripheral surface of the sheet feeding roller 14 by the urging force of the pressing spring 13. Then, the uppermost sheet 50 is separated by the rotation of the sheet feeding roller 14 into the separation block 20.
To the second separation rib 24 and the guide portion of the other separation block 20 after passing through the slit 25 between the guide portion 22 and the first separation rib 23 located on the hopper 12 side.
It passes through a slit 26 between 22 and 22. At this time, when the lowermost sheet 50 is conveyed together with the uppermost sheet 50, the conveyance is blocked by the first separating rib 23 on the hopper 12 side as in the above-described embodiment. . Then, the lower sheet 50 that has passed through the slit 25 on the first separating rib 23 is
The separation ribs 24 again prevent their transport. Therefore, the lower-side sheets that are double-fed are reliably prevented from being conveyed.

In the above embodiment, the first separating rib and the second separating rib are arranged side by side in the sheet feeding direction, but the separating ribs may be arranged further in the sheet feeding direction.

(Effects of the Invention) According to the present invention described above, even if double feeding of sheets is reliably prevented and the leading end of the sheet to be fed is curled downward, It can be reliably transported by the separating member.

In addition, in the present invention, the plurality of first separating members and the plurality of second separating members are both provided in the width direction orthogonal to the sheet conveying direction, and the tip portions of both are close to the peripheral surface of the sheet feeding roller, that is, Since they are arranged so as to face each other with a slight gap, the tips of the first separating member and the second separating member, especially the second separating member.
Between the tip of the separating member and the peripheral surface of the paper feed roller, a conveyance force due to a frictional force acts on the paper at a plurality of positions in the width direction of the paper.

For this reason, according to the present invention, the sheet is conveyed by a plurality of evenly divided conveying forces, so that the sheet can be fed straight after being prevented from double feeding. As a result, the leading edge of the paper can be easily adjusted, and therefore, when the paper feeding device of the present invention is used as a paper feeding device of an image forming apparatus such as a copying machine, copy defects do not occur.

[Brief description of the drawings]

1 is a schematic configuration diagram showing a sheet feeding device according to a first embodiment of the present invention, FIG. 2 (a) is a schematic configuration diagram of a sheet feeding device according to a second embodiment of the present invention, and FIG. b) is a perspective view of the main part thereof, FIGS. 3 (a) and 3 (b) are configuration diagrams of a conventional sheet feeding device, and FIGS. 4 (a) and 4 (b) are diagrams of the conventional sheet feeding devices. It is a block diagram which shows another example. 12 …… Hopper, 13 …… Push spring, 14 …… Paper feed roller, 15 …… First separation rib, 16 …… Second separation rib, 20 ……
Separation block, 23 ... First separation rib, 26 ... Second separation rib.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-56-99139 (JP, A) Actually open 2-69639 (JP, U) Actually open 63-104344 (JP, U) Actually open 51- 16380 (JP, U) Actual Kaihei 1-70740 (JP, U)

Claims (2)

(57) [Claims] 1. A flat plate-shaped hopper on which a large number of sheets of paper are placed, a paper feed roller arranged to face a side portion of the hopper on the paper feed direction side, and the hopper on the paper feed roller. An urging means for urging the side of the paper feed side of the hopper toward the paper feed roller to bring the upper paper into contact with the hopper, and a side of the paper feed side of the hopper that is displaced in the paper feed direction. Having a first separating member and a second separating member, both of which are arranged so as to be inclined downwardly on the paper side, and the first separating member and the second separating member are orthogonal to the conveying direction of the paper. A plurality of sheets are provided in the width direction of the sheet feeding device, and each of them has a sheet separating unit whose front end is close to the peripheral surface of the sheet feeding roller. 2. A flat plate-shaped hopper on which a large number of sheets are placed, a paper feed roller arranged to face a side portion of the hopper on the side of the paper feed direction, and a paper feed roller. Biasing means for urging the side of the paper feed side of the hopper toward the paper feed roller in order to bring the paper on the hopper into contact with the paper; A sheet separating unit arranged downstream of the sheet feeding roller in the sheet conveying direction conveyed by the sheet feeding roller, the sheet separating unit being displaced from each other in the sheet feeding direction, Further, a plurality of first separating members and a second separating member are provided, both of which are provided in a width direction orthogonal to the transport direction of the paper, and the surfaces on the paper side are both inclined downwardly, the first separating member and the second separating member. It is placed above the separating member so as to face the sheet with a gap allowing the passage of the sheet. Paper feeding device is composed of a guide member.