This application claims priority from Japanese Patent Application No. 2014-031688 filed on Feb. 21, 2014, the entire subject-matter of which is incorporated herein by reference.
The present disclosure relates to a sheet separating apparatus.
There has been disclosed an example of a sheet separating apparatus. This sheet separating apparatus has a stacking unit, a separation roller, and a separation piece. The stacking unit has a sheet supporting surface capable of supporting a plurality of sheets stacked. The separation roller rotates around a first shaft center parallel to the width direction of the sheet supporting surface, thereby coming into contact with a sheet fed from the stacking unit and conveying the sheet to the downstream side in a conveyance direction perpendicular to the width direction. The separation piece faces the separation roller, and separates sheets one at a time in cooperation with the separation roller.
However, in the above-described related-art sheet separating apparatus, according to whether the number of sheet stacked on the sheet supporting surface is large or small, a trajectory of the leading end of the sheet fed from the stacking unit to the separation roller may be likely to significantly vary. For example, in the related-art sheet separating apparatus, as will be described below, according to whether the number of sheet stacked on the sheet supporting surface is large or small, the sheet separating apparatus may not reliably separate the sheets one at a time.
For example, it is assumed that the separation roller is provided to be able to contact each sheet which is fed from the stacking unit, from a side that is opposite to a side facing the sheet supporting surface, such that the uppermost sheet of the sheets supported on the sheet supporting surface is fed to the separation roller. A nip position is defined as a position where a sheet is nipped by the separation roller and the separation piece when the sheet is fed.
In this case, if the number of sheets stacked on the sheet supporting surface is large, the trajectory of the leading end of the uppermost sheet passes a position close to the separation roller and proceeds toward the nip position. Therefore, the leading end of the corresponding sheet easily reaches the nip position. However, in this case, simultaneous conveyance of sheets may occur. Meanwhile, if the number of sheets stacked on the sheet supporting surface is small, the trajectory of the leading end of the uppermost sheet passes a position separated from the separation roller and close to the separation piece, and proceeds toward the nip position. Therefore, the leading end of the corresponding sheet may be unlikely to reach the nip position. In this case, failure of sheet conveyance may occur.
Also, the sheet separating apparatus is required to be reduced in size.
Therefore, it is preferably to provide a sheet separating apparatus capable of implementing a decrease in size and capable of reliably separating sheets, one at a time, regardless of the number of sheets stacked on a sheet supporting surface.
According to one aspect of the disclosure, a sheet separating apparatus comprises: a stacker including a sheet supporting surface for supporting a sheet; a separation roller configured to rotate around a first shaft center that is parallel to a width direction of the sheet supporting surface, wherein the separation roller is configured to contact the sheet fed from the stacker and to convey the sheet to a downstream side in a conveyance direction that is perpendicular to the width direction; a separation piece, which faces the separation roller, and which is configured to separate the sheet one at a time in cooperation with the separation roller, the separation roller and the separation piece being configured to nip the sheet being fed at a first nip position; and a pinch roller, which is provided on an upstream side with respect to the first nip position in the conveyance direction, and which is configured to abut on the separation roller so as to be rotatable around a second shaft center, which is parallel to the width direction, by a rotation of the separation roller, wherein the pinch roller has a portion overlapping the separation piece as seen from the width direction.
In another aspect of the disclosure, a sheet separating apparatus comprises: a stacker that has a sheet supporting surface for supporting a plurality of sheets stacked; a separation roller configured to rotate around a first shaft center that is parallel to a width direction of the sheet supporting surface, wherein the separation roller is configured to contact a sheet fed from the stacker and to convey the sheet to a downstream side in a conveyance direction that is perpendicular to the width direction; a separation piece, which face the separation roller, and which is configured to separate the sheet one at a time in cooperation with the separation roller, the separation roller and the separation piece being configured to nip the sheet being fed at a first nip position; and a pinch roller, which is provided on the upstream side from the first nip position in the conveyance direction, and which is configured to abut on the separation roller so as to be rotatable around a second shaft center, which is parallel to the width direction, by a rotation of the separation roller, the separation roller and the pinch roller are configured to nip the sheet being fed at a second nip position, wherein as seen from the width direction, an extension plane extending from the sheet supporting surface toward the downstream side in the conveyance direction, with a gap from an outer circumferential surface of the separation roller, and wherein the outer circumferential surface of the pinch roller includes an arc that extends from a position adjacent to an end portion of the sheet supporting surface at the downstream side in the conveyance direction to the second nip position while swelling toward the separation roller.
The present disclosure is illustrated, and not limited, by way of example by the accompanying figures in which like reference numerals indicate similar elements.
Hereinafter, first to third illustrative embodiments will be described with reference to the accompanying drawings.
(First Illustrative Embodiment)
As shown in
<Configuration>
As shown in
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The discharge tray 92 is positioned on the lower side from the feeding tray 91. After the image of a sheet SH is read by the read sensor 3S, the sheet SH is conveyed by the conveyor 4, thereby being discharged onto the discharge tray 92.
The conveyor 4 defines a conveyance path P1 as a space surrounded by guide surfaces, a conveying roller (to be described below), and the like. The guide surfaces extend inside the opening/closing unit 9 so as to be capable of abutting on both sides of each sheet SH. The conveyance path P1 first includes a portion extending almost horizontally from an end portion of the sheet supporting surface 91A of the feeding tray 91 positioned on the downstream side in the conveyance direction, toward the left side. Next, the conveyance path P1 includes a portion curved downward and making a U-turn. Next, the conveyance path P1 includes a short portion extending toward the right side along the read surface 82A. Finally, the conveyance path P1 includes a portion inclined from the downstream side of the read surface 82A in the conveyance direction toward the upper right side and leading to the discharge tray 92.
The conveyance direction of a sheet SH which is conveyed by the conveyor 4 may be a leftward direction in the substantially horizontal portion of the upper path of the conveyance path P1, and varies to be a rightward direction in the portion of the conveyance path P1 curved downward and making the U-turn, and may be a rightward direction in the portion of the lower path of the conveyance path P1 passing the read surface 82A and leading to the discharge tray 92. The conveyance direction is perpendicular to the front-rear direction which is the width direction of the sheet supporting surface 91A.
As shown in
As shown in
The separation roller 42 is provided at a position which faces the guide surface 93B of the chute member 93 from the above and is close to the second sheet supporting surface 93A of the chute member 93. The separation roller 42 is fit on a drive shaft 42S, which has a first shaft center X1 extending in the front-rear direction, as a central axis. The separation roller 42 is a roller which rotates around the first shaft center X1 integrally with the drive shaft 42S. That is, the separation roller 42 is provided so as to be able to contact each sheet SH from a side that is opposite to a side facing the sheet supporting surface 91A if the corresponding sheet SH is fed from the feeding tray 91.
On the drive shaft 42S, a holder 42F is supported so as to be able to swing around the first shaft center X1. The holder 42F protrudes from the drive shaft 42S toward the right side.
The feeding roller 41 is provided on the right side with respect to the separation roller 42, that is, on the upstream side with respect to the separation roller 42 in the conveyance direction such the feeding roller 41 faces the second sheet supporting surface 93A of the chute member 93 from the above. The feeding roller 41 is supported on the right portion of the holder 42F so as to be rotatable around a third shaft center X3 extending in the front-rear direction. That is, the feeding roller 41 is provided so as to be able to contact the sheet SH from the side that is opposite to the side facing the sheet supporting surface 91A if the sheet SH are supported on the sheet supporting surface 91A of the feeding tray 91. Although not shown in the drawings, on the holder 42F, a transmission gear group (not shown) is provided so as to transmit a rotation drive force from the drive shaft 42S to the feeding roller 41.
As shown in
The position of the feeding roller 41 shown in
If a plurality of sheets SH is supported on the sheet supporting surface 91A of the feeding tray 91, the feeding roller 41 rotates around the third shaft center X3, thereby applying a conveyance force to the uppermost sheet SH, thereby sending the corresponding sheet SH toward the separation roller 42. If the sheet SH is fed from the feeding tray 91, that is, from the upstream side in the conveyance direction, the separation roller 42 rotates while being in contact with the sheet SH, thereby conveying the sheet SH toward the left side, that is, toward the downstream side in the conveyance direction, along the substantially horizontal portion of the upper path of the conveyance path P1.
As shown in
The sheet supporting surface 91A includes a protruding portion 93D which protrudes toward the left side so as to penetrate into the left portion of the opening 93H. The left end edge of the protruding portion 93D configures an end portion 91EE which is a portion of the end portion 91E of the sheet supporting surface 91A positioned on the downstream side in the conveyance direction. That is, the end portion 91EE which is included in the end portion 91E of the sheet supporting surface 91A positioned on the downstream side in the conveyance direction and faces the opening 93H is positioned on the right side from the other portion of the end portion 91E, that is, on the upstream side from the other portion of the end portion 91E in the conveyance direction. In wall surfaces extending downward from the front end edge and rear end edge of the protruding portion 93D, a pair of front and rear shaft receiving portions 93T is formed in a recess shape. The shaft receiving portions 93T are positioned on the right side with respect to the shaft receiving portions 93S.
As shown in
As shown in
The base portion 151 is formed in a substantially rectangular plate shape. At the right portion of the top surface of the base portion 151, the inclined surface 130 is formed. The inclined surface 130 is inclined toward the upper left side. On the left portion of the top surface of the base portion 151, the separation piece 43 is attached.
The front protruding portion 152 protrudes from the front left corner of the base portion 151 toward the front side, and then is curved so as to protrude toward the right side. The rear protruding portion 152 protrudes from the rear left corner of the base portion 151 toward the rear side, and then is curved so as to protrude toward the right side. At the right end portions of the protruding portions 152, shaft parts 152S are formed, respectively. The front shaft part 152S and the rear shaft part 152S are cylindrical shafts, which have a pivot shaft center X150 extending in the front-rear direction, as a central axis. The pivot shaft center X150 is positioned on the right side with respect to the first shaft center X1, that is, on the upstream side with respect to the separation roller 42 in the conveyance direction. The front shaft part 152S and the rear shaft part 152S protrude in opposite directions.
As shown in
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A first nip position N1 is defined as a position where a sheet SH is nipped by the separation roller 42 and the separation piece 43 as shown in
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More specifically, as shown in
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The bottom wall portion 121 of the holding unit 120 is positioned on the lower side with respect to the base portion 151 of the separation piece holder 150. The side wall portion 122 of the front side of the holding unit 120 and the front pinch roller 100 are positioned between the base portion 151 and front protruding portion 152 of the separation piece holder 150. The side wall portion 122 of the rear side of the holding unit 120 and the rear pinch roller 100 are positioned between the base portion 151 and rear protruding portion 152 of the separation piece holder 150.
As shown in
Between the bottom wall portion 121 of the holding unit 120 and the guide member 94, a compression spring 100T is disposed. The holding unit 120 swings around the fourth shaft center X4, whereby the pinch rollers 100 advance or retreat with respect to the separation roller 42. The compression spring 100T presses the bottom wall portion 121 upward, whereby the pinch rollers 100 are pressed against the separation roller 42. As a result, each pinch roller 100 may be driven to rotate around the second shaft center X2 by the separation roller 42 while abutting on the separation roller 42.
A second nip position N2 is defined as a position where a sheet SH is nipped by the separation roller 42 and the pinch rollers 100 as shown in
As shown in
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As seen from the front-rear direction, the extension plane E1 extending from the sheet supporting surface 91A toward the downstream side in the conveyance direction extends below the outer circumferential surface 42A of the separation roller 42 with a gap. As seen from the front-rear direction, the outer circumferential surface 100A of each pinch roller 100 (main pinch roller body 101) includes an arc 100C. The arc 100C extends from a position adjacent to the end portion 91EE which is included in the end portion 91E of the sheet supporting surface 91A positioned on the downstream side in the conveyance direction, to the second nip position N2, while swelling upward toward the separation roller 42.
As shown in
The conveyor 4 includes a conveying roller 45 having a large diameter, a curved guide surface 45G, and pinch rollers 45P and 45Q, which are provided in the portion of the conveyance path P1 curved downward and making the U-turn. The outer circumferential surface of the conveying roller 45 forms an inner guide surface of the portion of the conveyance path P1 curved downward and making the U-turn. The curved guide surface 45G is disposed with a predetermined gap from the outer circumferential surface of the conveying roller 45. The curved guide surface 45G forms an outer guide surface of the portion of the conveyance path P1 curved downward and making the U-turn. The conveying roller 45 conveys each sheet SH to the read surface 82A, in cooperation with the pinch rollers 45P and 45Q abutting on the outer circumferential surface of the conveying roller 45.
The conveyor 4 includes a pressing member 49 which is disposed at a position facing the read surface 82A from the above. If a sheet SH is conveyed from the conveying roller (45), the pressing member 49 presses the sheet SH from the above, thereby coming the sheet SH into contact with the read surface 82A.
The conveyor 4 includes a discharging roller 48 and pinch rollers 48P which are disposed in a portion of the conveyance path P1 positioned on the right side with respect to the pressing member 49 and inclined upward. The discharging roller 48 and the pinch rollers 48P are adjacent to the discharge tray 92. If a sheet SH passes the read surface 82A, the discharging roller 48 and the pinch rollers 48P discharge the sheet SH onto the discharge tray 92.
<Image Reading Operation>
In the image reading apparatus 1, in a case of reading the image of a document supported on the document supporting surface 81A, the scanning mechanism (not shown) of the reading unit 3 operates such that the read sensor 3S moves in the left-right direction between the lower side of the left end edge of the document supporting surface 81A and the lower side of the right end edge of the document supporting surface 81A, whereby the read sensor 3S reads the image of the document supported on the document supporting surface 81A. Thereafter, the scanning mechanism (not shown) operates such that the read sensor 3S moves from the right end side to the left end side in the reading unit 3, thereby returning to the original position.
Also, in the image reading apparatus 1, in a case of reading the images of sheets SH put on the feeding tray 91, the scanning mechanism (not shown) of the reading unit 3 operates such that the read sensor 3S stops at a predetermined read position below the read surface 82A. The read sensor 3S which is at the predetermined read position is located on the downstream side with respect to the separation roller 42 in the conveyance direction. If the sheets SH on the feeding tray 91 are sequentially conveyed along the conveyance path P1 by the conveyor 4, since each sheet SH passes the upper side of the read sensor 3S being at the predetermined read position while being in contact with the read surface 82A, the read sensor 3S reads the image of the corresponding sheet SH. After the image of the sheet SH is read, the sheet SH is discharged onto the discharge tray 92 by the discharging roller 48 and the pinch rollers 48P.
<Advantages>
In the image reading apparatus 1 of the first illustrative embodiment, as shown in
Meanwhile, in the image reading apparatus 1, as shown in
That is, in the image reading apparatus 1, the leading end of each sheet SH is nipped at the second nip position N2 by the separation roller 42 and the pinch rollers 100, and then reaches the first nip position N1. Therefore, regardless of the number of sheets SH stacked on the sheet supporting surface 91A, the trajectory of the leading end of each sheet SH which is fed from the feeding tray 91 to the separation roller 42 is stable. Since the leading end of each sheet SH which is conveyed along the stable trajectory reaches the first nip position N1 positioned on the downstream side with respect to the second nip position in the conveyance direction, it is possible to stabilize the accuracy of separation of each sheet SH at the first nip position N1.
Also, in the image reading apparatus 1, if the separation piece 43 is simply arranged in series with the pinch rollers 100 in the conveyance direction, that is, in the left-right direction, in the substantially horizontal portion of the upper path of the conveyance path P1, a space (the length in the conveyance direction) for disposing the separation piece 43 and the pinch rollers 100 needs at least a length which is the sum of the length of the separation piece 43 in the conveyance direction and the length of one pinch roller 100 in the conveyance direction, that is, the outside diameter of one pinch roller body 101. Therefore, it becomes difficult to reduce the size of the apparatus in the left-right direction which is the conveyance direction. In contrast to this, in the image reading apparatus 1, as shown in
Therefore, in the image reading apparatus 1 of the first illustrative embodiment, regardless of the number of sheets SH stacked on the sheet supporting surface 91A, it is possible to reliably separate the sheets SH one at a time. Further, it is possible to reduce the size of the apparatus.
Also, in the image reading apparatus 1, as shown in
Further, in the image reading apparatus 1, as shown in
Also, in the image reading apparatus 1, as seen from the front-rear direction, the inclined surface 130 includes the portions 130D which overlap the pinch rollers 100, respectively. Therefore, in the image reading apparatus 1, even in a section between the sheet supporting surface 91A and the pinch rollers 100, it is possible to reliably guide the leading end of each sheet SH by the inclined surface 130.
Further, in the image reading apparatus 1, as shown in
Also, in the image reading apparatus 1, the pinch rollers 100 are held by the holding unit 120 swinging around the fourth shaft center X4 positioned on the right side with respect to the separation roller 42, that is, on the upstream side with respect to the separation roller 42 in the conveyance direction. Therefore, for example, as compared to a case of using a configuration in which the holding unit moves linearly, it is possible to reduce the size of the apparatus in the height direction Dh.
Further, in the image reading apparatus 1, the outer circumferential surface side of each main pinch roller body 101 is formed of rubber as the outer layer 100S of a corresponding pinch roller 100. Therefore, in the image reading apparatus 1, it becomes difficult for the leading end of a sheet SH being in contact with the outer layers 100S of the pinch rollers 100 to slip from the pinch rollers 100, and thus it is possible to more reliably guide the leading end of each sheet SH by the pinch rollers 100.
Also, in the image reading apparatus 1, since the separating performance of the separation roller 42 and the separation piece 43 is stable due to the pinch rollers 100, it is possible to stabilize the image reading quality of the read sensor 3S positioned on the downstream side with respect to the separation roller 42 in the conveyance direction.
(Second Illustrative Embodiment)
As shown in
In the image reading apparatus of the second illustrative embodiment, as shown in
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The side wall portion 222 of the front side of the holding unit 220 and the front pinch roller 100 are positioned between the base portion 151 and front protruding portion 152 of the separation piece holder 150. The side wall portion 222 of the rear side of the holding unit 220 and the rear pinch roller 100 are positioned between the base portion 151 and rear protruding portion 152 of the separation piece holder 150. The holding unit 220 swings around the fourth shaft center X24, whereby the pinch rollers 100 advance or retreat with respect to the separation roller 42.
In the image reading apparatus of the second illustrative embodiment configured as described above, similarly to the image reading apparatus 1 of the first illustrative embodiment, regardless of the number of sheets SH stacked on the sheet supporting surface 91A, it is possible to reliably separate the sheets SH one at a time. Further, it is possible to reduce the size of the apparatus.
Also, in this image reading apparatus, the pinch rollers 100 are held by the holding unit 220 swinging around the fourth shaft center X24 positioned on the downstream side with respect to the separation roller 42 in the conveyance direction. Therefore, for example, as compared to a case of using a configuration in which the holding unit moves linearly, it is possible to reduce the size of the apparatus in the height direction Dh shown in some drawings such as
(Third Illustrative Embodiment)
As shown in
In the image reading apparatus of the third illustrative embodiment, in the opening 93H (not shown), a pair of front and rear protrusions 393T are formed. The protrusions 393T protrude upward from the bottom of the opening 93H (not shown). Although not shown in
The linear motion type holding unit 320 is formed by integrally forming a bottom wall portion 321 and a pair of front and rear side wall portions 322. The bottom wall portion 221 extends in the front-rear direction and has a rectangular plate shape, and the side wall portions 322 protrude upward and downward from the front end portion and rear end portion of the bottom wall portion 221, respectively. The bottom wall portion 321 has the same configuration as that of the bottom wall portion 121 of the first illustrative embodiment.
Although not shown in
The portions of the side wall portions 322 protruding downward from the bottom wall portion 321 are cut out upward from their lower end portions, whereby guide grooves 322S are formed.
The guide rails 393U formed on the protrusions 393T are inserted into the guide grooves 322S of the linear motion type holding unit 320, respectively. As a result, the linear motion type holding unit 320 is supported by the chute member 93 so as to be linearly movable in a vertical direction, and operates such that the pinch rollers 100 linearly advance or retreat with respect to the first shaft center X1.
In the image reading apparatus of the third illustrative embodiment configured as described above, similarly to the image reading apparatuses 1 of the first and second illustrative embodiments, regardless of the number of sheets SH stacked on the sheet supporting surface 91A, it is possible to reliably separate the sheets SH one at a time. Further, it is possible to reduce the size of the apparatus.
Also, in this image reading apparatus, the linear motion type holding unit 320 is not bulky in the left-right direction. Therefore, it is easy to reduce the size of the apparatus in the left-right direction.
Although the present invention has been described above on the basis of the first to third illustrative embodiments, the present invention is not limited to the above-described first to third illustrative embodiment, and can be appropriately modified and applied without departing from the scope of the present invention.
In the first illustrative embodiment, the separation roller 42 is provided so as to be able to contact the sheet SH fed from the feeding tray 91, from the side that is opposite to the side facing the sheet supporting surface 91A, such that the uppermost sheet SH is first fed to the separation roller 42. However, the present invention is not limited thereto. For example, the separation roller may be provided so as to be able to contact the sheet fed from the feeding tray, from the same side as the sheet supporting surface, such that the lowermost sheet is first fed to the separation roller.
In the illustrative embodiments, as seen from the width direction, the second shaft center X2 is on the extension plane E1 extending from the sheet supporting surface 91A toward the downstream side in the conveyance direction. However, the present invention is not limited thereto. As seen from the width direction, the second shaft center may be located across the extension plane, which extends from the sheet supporting surface toward the downstream side in the conveyance direction, from the separation roller.
In the illustrative embodiments, the outer layers 100S of the pinch rollers 100 are formed of rubber. However, the present invention is not limited thereto. At least the outer layers of the pinch rollers may be friction members such as elastomer or sponge. Alternatively, the whole of each pinch roller may be formed of a resin.
The present invention can be applied to apparatuses such as an image reading apparatus, an image forming apparatus, and a multi-function apparatus.
Number | Date | Country | Kind |
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2014-031688 | Feb 2014 | JP | national |
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Entry |
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Office Action issued in related Chinese patent application No. 201510087492.7, dated Nov. 4, 2016. |
Office Action from corresponding Japanese Patent Application No. P2014-031688, dated Jan. 31, 2017. |
Office Action from corresponding Chinese Patent Application 201510087492.7, dated Aug. 2, 2017. |
Number | Date | Country | |
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20150239691 A1 | Aug 2015 | US |