JPH1159934A - Paper feeder - Google Patents

Abstract

[PROBLEMS] To provide a sheet feeding device which prevents a sheet from being fed by a rolling element so as to reliably feed a plurality of stacked sheets one by one. SOLUTION: A plurality of read originals 2 stacked on each other are
A sheet feeder that separates sheets one by one and feeds the sheet in a predetermined feed direction while being in close contact with the surface of a roller body 12 b of the sheet feed roller 12. A flexible separating piece 1 that is arranged with a predetermined inclined posture along the feeding direction in a state of being sandwiched between
3, a back pressure spring 14 for pressing the leading end of the separating piece 13 in the feed direction against the surface of the roller body 12b of the paper feed roller 12.
And a posture holding member 15 which comes into contact with the back surface of the separation piece 13 and maintains the inclination posture of the separation piece 13 constant.

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 capable of separating and feeding a plurality of stacked sheets one by one.

[0002]

2. Description of the Related Art Generally, a reading apparatus or a printing apparatus has a built-in paper feeder for drawing a plurality of read originals or recording sheets as sheet bodies into the apparatus body one by one. In such a sheet feeding device, a plurality of sheets stacked on a sheet tray or the like are separated one by one and drawn into the apparatus main body while being in close contact with a roller surface of a sheet feeding roller. I have.

FIG. 5 is an enlarged cross-sectional view of a main part of a conventional paper feeder, showing the periphery of a paper feed roller when a sheet body is separated. As shown in FIG. In the case of (1), the leading ends of the plurality of stacked sheet bodies 20 are sandwiched between the sheet feeding rollers 22 by the separation pieces 21 arranged with a predetermined inclined posture along the feeding direction. Since the leading end side of the separation piece 21 in the feeding direction is pressed by the pressing portion 23a of the back pressure spring 23 with a predetermined pressing force against the feed roller 22, the leading end of the sheet body 20 is fed. The roller 22 is in close contact with the roller 22 in a displaced position, forming a wedge shape.
In this state, a predetermined space 25 is formed between the separation piece 21 and the back pressure spring 23 (the state of the separation piece 21 indicated by a virtual line in FIG. 5). Further, an auxiliary spring 24 that presses the sheet body 20 against the paper feed roller 22 is disposed upstream of the back pressure spring 23 in the feeding direction. Adhesive force is applied to the lowermost sheet body 20 to be fed, and an auxiliary conveying force is obtained.

[0004]

However, in the above-described conventional paper feeder, the leading end of the separation piece 21 in the feed direction is the back pressure spring 2.
3 is pressed only by the pressing portion 23a, and the separation piece 21 itself is usually formed to be easily bent.
In a state where the coefficient of friction between each of the multiple sheets 20 is high, for example, when the sheets are in a moisture-absorbing state in a high-humidity environment, as shown in FIG. The leading end abuts on the separation piece 21 to change its inclination posture greatly, and the back pressure spring 23 bends, so that the space 25 cannot be held (the state of the separation piece 21 shown by a solid line in FIG. 5). As a result, the angle between the leading end of the sheet member 20 and the separation piece 21 increases, and the resistance to the sheet member 20 located at the lowermost layer being separated and pulled out increases.
Further, since it is not possible to form a posture (wedge shape) that is sufficiently shifted from the overlapping position, the pressing force of the auxiliary spring 24 is insufficient, so that the adhesion between the sheet member 20 located at the lowermost layer and the sheet feeding roller 22 is not maintained. Since the auxiliary conveyance force is also insufficient, there is a problem that the lowermost sheet body 20 and the paper feed roller 22 run idle and are fed idly.

In view of the above, the present invention has been proposed in view of the above-mentioned point, and an idle feed by a rolling element is used to reliably feed a plurality of stacked sheets one by one. It is an object of the present invention to provide a sheet feeding device which prevents the occurrence of the sheet feeding.

[0006]

According to a first aspect of the present invention, there is provided a sheet feeding apparatus for separating a plurality of stacked sheets one by one to form a rolling element. A sheet feeding device that feeds in a predetermined feeding direction while being in close contact with a rolling surface, wherein a predetermined inclination is provided along a feeding direction in a state where tips of the plurality of sheets are sandwiched with respect to the rolling surface. A flexible separating piece arranged in a posture, pressing means for elastically pressing the leading end side of the separating piece in the feeding direction against the rolling surface with a predetermined load, and a rear face of the separating piece. And a posture holding member that abuts and keeps the inclination posture of the separation piece substantially constant.

According to this paper feeder, when a large number of sheets are sandwiched by the separation pieces, when the first sheet is separated, a state of a bundle in which the edges of each sheet are aligned is obtained. To form a wedge shape in which misalignment occurs. In the case of a sheet body that has absorbed moisture in a high-humidity environment, the wedge shape cannot be formed sufficiently due to the friction between the sheet bodies, and a force is exerted to push up and deform the separation piece. Since it is held substantially constant, a wedge shape is formed in which the leading ends of the sheet members are sufficiently displaced from each other along the appropriate inclined posture of the separation piece. Therefore, since the entering direction of the sheet body and the angle of the separation piece are maintained at the optimum angle, the resistance force when the sheet body is separated and sent out is always stable, and a plurality of stacked sheet bodies are stacked. Sheets are reliably fed out one by one, and sheet feeding can be prevented.

According to a second aspect of the present invention, there is provided the sheet feeding apparatus according to the first aspect, wherein the separating piece is formed of an elastic member, and the posture holding member is formed of the separating piece. It is made of a thin film member that is rigid with respect to.

According to this sheet feeding device, in addition to the effect of the sheet feeding device according to the first aspect, the separating piece is made of an elastic member, and the posture holding member is a thin film that is rigid with respect to the separating piece. Since the member is made of a member, even if the separation piece is made of a material that is likely to change in posture due to elastic deformation, the inclined posture can be maintained in an appropriate state by the thin film member.

Further, according to a third aspect of the present invention, in the paper feeder according to the first or second aspect, the posture holding member has a distal end provided with a pressing portion of the pressing means. It is arranged so as to be located further upstream in the feeding direction.

According to this paper feeding device, in addition to the effect of the paper feeding device according to claim 1 or 2, the posture holding member has its tip disposed upstream of the pressing portion of the pressing means in the feeding direction. As a result, the holding force of the posture holding member and the pressing force of the back pressure spring, which are loads when separating the sheet body, act on different positions of the separation piece, and as a result, the load on the sheet body is reduced. Therefore, the sheet body can be smoothly fed.

A paper feeder according to a fourth aspect of the present invention is the paper feeder according to any one of the first to third aspects, wherein the pressing means includes a pressing part extending from a base end thereof. This is a leaf spring that is formed in a bent shape with respect to, and is disposed with a predetermined space between itself and the separation piece except for the pressing portion.

According to this sheet feeding device, in addition to the effects of the sheet feeding device according to any one of the first to third aspects, the sheet member may be made of a rigid material or may be in a state where the bundle is not easily broken. In some cases, even with the posture holding member, it may not be possible to maintain an appropriate inclined posture.However, the leaf spring as the pressing means has a predetermined space between itself and the separation piece other than the pressing portion. Since it is arranged, the posture holding member can be deformed in the direction in which the inclination angle increases with the separation piece, and at this time, the opening of the pressing portion of the pressing means is prevented, so that the occurrence of jam due to multiplex feeding is prevented. Can be prevented.

According to a fifth aspect of the present invention, there is provided the sheet feeding apparatus according to any one of the first to fourth aspects, wherein the sheet feeding apparatus is located upstream of the pressing portion of the pressing means in the feeding direction. , An auxiliary spring that presses the sheet body against the rolling surface is disposed.

According to this sheet feeding device, in addition to the effect of the sheet feeding device according to any one of claims 1 to 4, a rolling surface is provided upstream of the pressing portion of the pressing means in the feeding direction. Since the auxiliary spring that presses the sheet member is disposed with respect to the sheet member, the sheet member can be more securely brought into close contact with the rolling surface by the auxiliary spring.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a schematic cross-sectional view schematically showing the entirety of a reader incorporating a paper feeder according to an embodiment of the present invention. The paper feeder shown in FIG. A plurality of read originals (sheets) 2 placed near each other are separated one by one from the lowermost layer and transport rollers 3 in the reading device main body.
It is sent to. The reading device reads a line in the main scanning direction of the read document 2 at the reading position S by a line image sensor via an optical system. After the reading is completed, the read document 2 is discharged to the discharge port 5 by the discharge roller 4. In this figure, a reading head, a light source, and the like are not shown, and a description thereof will be omitted.

FIG. 2 is an enlarged cross-sectional view of a main part showing the periphery of the paper feed roller in FIG. 1. Referring to this figure, the paper feeder will be described. The paper device includes a pull-in roller 10 that pulls in the read document 2 near the paper feed port 1, a pressing arm 11 that presses the read document 2 against the pull-in roller 10, a spring 11 a that urges the pressing arm 11 from above, a pull-in roller 10. The paper feed roller 12 feeds one of the lowermost layers of the read original 2 drawn into the transport roller 3 to the transport roller 3, and is disposed with a predetermined inclination posture with respect to the paper feed roller 12 in a state where the leading end of the read original 2 is sandwiched. The separation piece 13, a back pressure spring 14 for pressing the separation piece 13 against the paper feed roller 12 with a predetermined load, and a separation pressure provided between the separation piece 13 and the back pressure spring 14 so that the inclination posture of the separation piece 13 is substantially constant. Figure to hold Holding member 15 and the back pressure spring 14,
The reading original 2 is fed to the feed roller 1 further upstream in the feeding direction.
An auxiliary spring 16 for pressing against the second spring 2 is roughly provided.

The pull-in roller 10 is constructed by winding a roller body 10b made of an elastic member such as rubber around a rotating body 10a which is rotated by the driving force of a stepping motor (not shown). Such a roller body 10b
Are rotated via a deceleration mechanism or a one-way clutch (not shown), and are disposed substantially at the center in the width direction with respect to the feeding direction of the read original 2.

The pressing arm 11 presses the reading document 2 in a state where a large number of read originals 2 are bundled, and applies a biasing force in the direction of the drawing roller 10 by a spring 11a. That is, the lowermost read original 2 is brought into close contact with the draw-in roller 10 by the pressing arm 11, and is fed out downstream in the feed direction. Further, the force of feeding the read document 2 to the downstream side in the feed direction by the pull-in roller 10 does not work when the read document 2 starts receiving a driving force by a sheet feed roller 12 described later.
This is realized by applying a peripheral speed difference and a one-way clutch to the pull-in roller 10 and the paper feed roller 12.

The paper feed roller 12, like the draw-in roller 10, is constructed by winding a roller body 12b made of an elastic member such as rubber around a rotating body 12a rotated by the driving force of a stepping motor (not shown). ing.
The roller main body 12b is configured to rotate via a speed reduction mechanism or a one-way clutch (not shown), and is disposed substantially at the center in the width direction with respect to the feeding direction of the read original 2.

FIG. 3 shows the sheet feeding roller 1 shown in FIG.
FIG. 2 is an exploded perspective view of a main part, showing an upper part of the periphery from an obliquely lower part. Referring to this figure, the separating piece 13 is made of a flexible elastic member such as silicon rubber. The document 2 is arranged at a predetermined inclination angle along the feed direction in a state where the leading end of the read document 2 is sandwiched between the feed rollers 12. The base end of the separation piece 13 is engaged with the vertical projection 6a of the inner wall of the apparatus via the through hole 13a with a back pressure spring 14 and a posture holding member 15 described later interposed therebetween. The leading end side in the feed direction, which is the other end side with respect to the base end portion of the separation piece 13, is the roller body 12 of the sheet feeding roller 12.
b.

The back pressure spring 14 is made of a resilient bending member made of metal, for example. . Except for the pressing portion 14a of the back pressure spring 14, the separation piece 1
3 to form a predetermined space 17. The base end of the back pressure spring 14 is engaged with the vertical projection 6a via the through hole 14b in a state where the separation piece 13 and the posture holding member 15 are overlapped from above.

The posture holding member 15 is made of a thin film member such as PET (polyethylene terephthalate resin), which is rigid with respect to the separation piece 13. Attempts to deform the separation piece 13 by the conveyance force of the paper feed roller 12, while maintaining the inclination posture of the separation piece 13 in an appropriate state substantially constant. The base end portion of the posture holding member 15 has a through hole 15a sandwiched between the separation piece 13 and the back pressure spring 14.
And is engaged with the vertical projection 6a through the hole.

The auxiliary spring 16 is made of, for example, a resilient bending member made of metal or the like. The auxiliary spring 16 presses the leading end of the read original 2 in the feed direction against the paper feed roller 12 by the pressing part 16a to make the original close contact. By such a pressing portion 16a of the auxiliary spring 16, a close contact force is given between the paper feed roller 12 and the lowermost read original 2 to be fed, thereby obtaining an auxiliary conveyance force. The base end of the auxiliary spring 16 holds the through-hole 1 in such a manner as to hold down the base end of the separating piece 13, the back pressure spring 14, and the posture holding member 15, which are overlapped with each other.
It is engaged with a lateral protrusion 6b formed on the inner wall of the device via 6b.

The separating piece 13, the back pressure spring 14, the attitude holding member 15, and the auxiliary spring 16 are assembled integrally with each other, and the base ends of the devices are located upstream of the feed roller 12 in the feed direction. While being fixed to the inner wall,
The leading end side in each feeding direction is arranged near the position where the sheet feeding roller 12 and the leading ends of the plurality of read originals 2 are in close contact. Further, the tip of the posture holding member 15 is disposed so as to be located on the upstream side in the feed direction from the pressing portion 14a of the back pressure spring 14.

Next, the essential points of the operation of the sheet feeding device having the above configuration will be described in detail with reference to FIGS.

FIG. 4 is an enlarged cross-sectional view of a main portion showing the vicinity of the position where the paper feed roller 12 and the leading end of the read original 2 in FIG. 2 are in close contact with each other. As shown in FIG. ,
When the paper feed roller 12 rotates in the feed direction, one of the lowermost layers of the multiplied read originals 2 is sent out in the feed direction while closely contacting the roller body 12b.

At this time, since the read originals 2 are attracted to each other by friction or moisture absorption, a plurality of read originals 2 are dragged by one of the lowermost layers.
Move together in the feed direction, and the leading ends of the plurality of read originals 2 come into contact with the separation pieces 13.

In the state where the leading edge of the read original 2 is in contact with the separating piece 13,
Is pressed, but the inclined position of the separation piece 13 itself is held substantially constant by the position holding member 15 abutting on the back surface thereof. That is, the inclination of the separation piece 13 is maintained to the same extent as when the leading end of the read document 2 is not in contact.

As a result, the leading ends of the plurality of read originals 2 are maintained in a wedge shape in which the leading ends of the plurality of read originals 2 are sufficiently overlapped and displaced along the inclination posture of the separation piece 13, and only one of the lowermost layers is the roller body 12 b of the feed roller 12. As a result, the leading end of the wedge-shaped read document 2 is pressed against the surface of the roller body 12b by the pressing portion 16a of the auxiliary spring 16.

Subsequently, when the paper feed roller 12 rotates, only the lowermost one sheet of the read original 2 is moved to the roller body 12b.
The sheet is sent out along the feeding direction while being held between the separation pieces 13 while being in close contact with the surface.

Then, when the read original 2 passes near the pressing position of the separation piece 13 pressed by the pressing portion 14a of the back pressure spring 14, the pressing portion 14 is integrated with the separation piece 13.
a is slightly pushed up, and the read original 2 is sent out without being stagnated while being sandwiched between the separation pieces 13.

As described above, the plurality of read originals 2 are separated pieces 1
3, the holding force of the posture holding member 15 acting as a load on the separation pieces 13 to be pushed up by the plurality of read originals 2 is determined by the separation pieces 13.
On the other hand, while the pressing force of the back pressure spring 14 acts on the contacting portion of the separation piece 13 with the paper feed roller 12 which is located at a position different from the position holding member 15, and as a result, The load on the read document 2 is reduced, and the read document 2 is sent out smoothly.

Therefore, according to the paper feeder having the above-described configuration and operation, when a large number of read originals 2 are sandwiched by the separation pieces 13, the leading end of the integrated read original 2 is Since the separation piece 13 is held at a substantially constant inclination by the position holding member 15, the leading end of the read document 2 is moved along the appropriate inclination of the separation piece 13. Since the wedges are kept sufficiently displaced from each other, the plurality of read originals 2 stacked on each other are surely sent out one by one in close contact with the paper feed roller 12 to prevent the paper feed roller 12 from being idlely fed. can do.

In addition, a rigid sheet material,
When the bundle is difficult to collapse, the reading document 2 may enter the bundle without forming the wedge shape, and the separation piece 13 may not be able to hold an appropriate inclined posture even with the posture holding member 15. Since the back pressure spring 14 is disposed with a predetermined space 17 between the back pressure spring 14 and the separation piece 13 except for the pressing portion 14a, the posture holding member 15
The deformation in the direction in which the inclination angle is increased together with 3 is allowed. At that time, the opening of the pressing portion 14a of the back pressure spring 14 is prevented, so that it is possible to prevent the occurrence of a jam due to multiple feeding.

In the above embodiment, the paper feeding device is described as being built in the reading device. However, the present invention is not particularly limited to this, and the paper feeding device may be applied to recording paper in a printing device.

Further, instead of the back pressure spring 14, a configuration may be adopted in which the leading end of the separation piece 13 in the feed direction is pressed against the paper feed roller 12 by a resin holder and a compression spring.

[0039]

As described above, according to the sheet feeding apparatus of the first aspect of the present invention, when a large number of sheets are sandwiched by the separation pieces, the first sheet is separated. At this time, the sheet forms a wedge shape in which the ends of each sheet member are misaligned from the state of the bundle. In the case of a sheet body that has absorbed moisture in a high-humidity environment, the wedge shape cannot be formed sufficiently due to the friction between the sheet bodies, and a force is exerted to push up and deform the separation piece. Since it is held substantially constant, a wedge shape is formed in which the leading ends of the sheet members are sufficiently displaced from each other along the appropriate inclined posture of the separation piece. Therefore, since the entering direction of the sheet body and the angle of the separation piece are maintained at the optimum angle, the resistance force when the sheet body is separated and sent out is always stable, and a plurality of stacked sheet bodies are stacked. Sheets are reliably fed out one by one, and sheet feeding can be prevented.

According to the paper feeding device of the invention described in claim 2, in addition to the effect of the paper feeding device described in claim 1, the separating piece is made of an elastic member, and the posture holding member is made of the elastic member. Since the separation piece is made of a thin film member that is rigid with respect to the separation piece, even if the separation piece is made of a material that easily changes in posture due to elastic deformation, the inclined posture can be maintained in an appropriate state by the thin film member.

Further, according to the sheet feeding device of the invention described in claim 3, in addition to the effect of the sheet feeding device described in claim 1 or 2, in addition to the effect of the posture holding member, the leading end of the posture holding member has a pressing means. Since it is arranged on the upstream side in the feed direction from the pressing portion, the holding force of the posture holding member, which is a load when separating the sheet body, and the pressing force of the back pressure spring act on another position of the separation piece, As a result, the load on the sheet member is reduced, so that the sheet member can be smoothly fed.

According to the sheet feeding device of the invention described in claim 4, in addition to the effect of the sheet feeding device according to any one of claims 1 to 3, the sheet body is made of a rigid material. Or if the bundle is difficult to collapse,
Even with the posture holding member, it may not be possible to maintain an appropriate inclined posture, but since the leaf spring as the pressing means is disposed with a predetermined space between the leaf spring and the separation piece other than the pressing portion, it is arranged. The posture holding member can be deformed together with the separating piece in the direction in which the inclination angle increases, and at this time, the opening of the pressing portion of the pressing means is prevented, so that the occurrence of a jam due to multiple feeding can be prevented. .

Further, according to the paper feeding device of the invention described in claim 5, in addition to the effect of the paper feeding device according to any one of claims 1 to 4, in addition to the effect of the paper feeding device from the pressing portion of the pressing means. Since the auxiliary spring that presses the sheet body against the rolling surface is disposed on the upstream side in the direction, the sheet body can be more securely brought into close contact with the rolling surface by the auxiliary spring.

[Brief description of the drawings]

FIG. 1 is a schematic overall cross-sectional view showing a schematic entirety of a reading device incorporating a paper feeding device according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part, in which a periphery of a paper feed roller in FIG. 1 is enlarged.

FIG. 3 is an exploded perspective view showing a main part of the paper feed roller shown in FIG.

FIG. 4 is an enlarged cross-sectional view of a main part, in which a vicinity of a position where a paper feed roller and a leading end of a read original in FIG.

FIG. 5 is an enlarged cross-sectional view of a main part of a conventional sheet feeding device, showing the periphery of a sheet feeding roller in an enlarged manner.

FIG. 6 is an enlarged cross-sectional view of a main part, in which the vicinity of a position where a paper feed roller and a leading end of a read original in FIG.

[Explanation of symbols]

 2 Document to be read (sheet body) 12 Paper feed roller 13 Separation piece 14 Back pressure spring 15 Posture holding member 16 Auxiliary spring 17 Space 20 Sheet body 21 Separator piece 22 Paper feed roller 23 Back pressure spring 24 Auxiliary spring 25 Space

Claims (5)

[Claims] 1. A sheet feeder for separating a plurality of stacked sheets one by one and feeding the sheets in a predetermined feed direction while being in close contact with a rolling surface of a rolling element, In the state where the leading end of the sheet member is sandwiched with respect to the rolling surface, a flexible separating piece arranged with a predetermined inclination posture along the feeding direction, and the leading end side of the separating piece in the feeding direction. A pressure unit that elastically presses against the rolling surface with a predetermined load; and a posture holding member that abuts against the back surface of the separation piece and holds the inclination posture of the separation piece substantially constant. Characteristic paper feeder. 2. The sheet feeding device according to claim 1, wherein the separation piece is made of an elastic member, and the posture holding member is made of a thin film member having rigidity with respect to the separation piece. 3. The sheet feeding device according to claim 1, wherein the posture holding member is disposed such that a tip thereof is located upstream of a pressing portion of the pressing means in a feeding direction. 4. The pressing means is a leaf spring formed in a bent shape from a base end portion to a pressing portion, and has a predetermined space between the pressing member and the separation piece except for the pressing portion. The sheet feeding device according to claim 1, wherein 5. An auxiliary spring that presses the sheet body against the rolling surface is disposed upstream of a pressing portion of the pressing unit in a feed direction. A paper feeder according to any one of the above.