SHEET FEEDER

A supply tray includes a first tray and a second tray. The first tray forms a first support surface including a downstream end of a sheet support surface in a feed direction. The second tray forms a second support surface adjacent to the first support surface from upstream in the feed direction. A friction member includes a first surface and a second surface. The first surface is provided to face a feed roller. The second surface is provided upstream of the first surface in the feed direction. The first surface is located farther from a rotation axis than the second support surface and the second surface are in a first direction which is parallel to a perpendicular line as viewed in a width direction. The perpendicular line is drawn from the rotation axis to the first surface in a state where the feed roller contacts the first surface.

REFERENCE TO RELATED APPLICATIONS

This application claims priority from Japanese Patent Application No. 2024-069554 filed on Apr. 23, 2024. The entire content of the priority application is incorporated herein by reference.

BACKGROUND ART

A sheet feeder that feeds a sheet such as a document is known.

SUMMARY

A document conveyance device, which is an example of a sheet feeder, includes a document placement portion, a pickup roller, and a friction member.

The document placement portion supports sheets in a stacked state. The pickup roller is rotatable about a rotation axis extending in a width direction of the document placement portion. The pickup roller feeds the uppermost sheet in a feed direction perpendicular to the width direction while contacting a surface of the uppermost sheet supported by the document placement portion.

The friction member is a cork sheet and so on, and is provided at a position facing the pickup roller in the document placement portion. The friction member contacts a bottom surface of the lowermost sheet supported by the document placement portion and applies a frictional force to the lowermost sheet, thereby suppressing a failure in which the lowermost sheet is fed in a state of being overlapped with an upper sheet when the upper sheet is fed.

In the document conveyance device, sheets that are deformed by having a tendency to warp or by warping due to moisture may be supported on the document placement portion in a stacked state. In this case, it is difficult to correct the deformed sheet by a pressing force when the pickup roller feeds the uppermost sheet, and it is difficult for the friction member to contact the bottom surface of the lowermost sheet. As a result, in the document conveyance device, the frictional force is unlikely to act on the sheets in a stacked state, and thus multi-sheet feed in which multiple sheets are fed in a stacked state is likely to occur (hereinafter also referred to as “stacked multi-sheet feed”). In the stacked multi-sheet feed, all the sheets placed on the document placement portion (document tray) are fed all at once, for example. When the stacked multi-sheet feed occurs, the sheets are jammed in a stacked state on the downstream side of the pickup roller in the feed direction, and thus misfeed is likely to occur.

In order to suppress such a problem, it is conceivable to make the friction member protrude more than the document placement portion and be closer to the rotation axis of the pickup roller so that the friction member easily contacts the bottom surface of the lowermost sheet. However, in order to keep the maximum number of sheets to be stacked, it is necessary to raise the upper limit position of the pickup roller by the height of the protrusion, and it is difficult to realize a reduction in size in the height direction.

In view of the foregoing, an example of an object of this disclosure is to provide a sheet feeder configured to suppress stacked multi-sheet feed even when deformed sheets are supported on a sheet support surface in a stacked state and to realize a reduction in size in a height direction.

According to one aspect, this specification discloses a sheet feeder including a supply tray, a feed roller, and a friction member. The supply tray includes a sheet support surface configured to support sheets in a stacked state. Thus, the supply tray supports sheets in a stacked state. The feed roller is rotatable about a rotation axis extending in a width direction of the sheet support surface. The feed roller is configured to contact a top surface of an uppermost sheet supported by the sheet support surface and to feed the uppermost sheet in a feed direction perpendicular to the width direction. Thus, the feed roller feeds the uppermost sheet in the feed direction. The friction member is provided to face the feed roller on the sheet support surface. The friction member is configured to contact a bottom surface of a lowermost sheet supported by the sheet support surface and to apply a frictional force to the lowermost sheet. Thus, the friction member applies the frictional force to the lowermost sheet. The supply tray includes a first tray forming a first support surface and a second tray forming a second support surface. The first support surface is a part of the sheet support surface. The first support surface includes a downstream end of the sheet support surface in the feed direction. The second support surface is at least part of a remaining part of the sheet support surface. The second support surface is adjacent to the first support surface from upstream in the feed direction. The friction member includes a first surface and a second surface. The first surface is provided to face the feed roller. The first surface is configured to contact the bottom surface of the lowermost sheet. The first surface is configured to contact the feed roller when there is no sheet supported by the sheet support surface. The second surface is provided upstream of the first surface in the feed direction. The second surface is configured to contact the bottom surface of the lowermost sheet. The first surface is located farther from the rotation axis than the second support surface and the second surface are in a first direction. The first direction is parallel to a perpendicular line as viewed in the width direction. The perpendicular line is drawn from the rotation axis to the first surface in a state where the feed roller contacts the first surface. Thus, the second surface reliably contacts the bottom surface of the lowermost sheet, while reducing the size of the sheet feeder in the first direction.

In the sheet feeder of the present disclosure, the second support surface of the second tray and the second surface of the friction member are located upstream of the first surface of the friction member in the feed direction. The first surface is located farther from the rotation axis than the second support surface and the second surface are in the first direction.

That is, a portion of the sheet supported by the sheet support surface, which contacts the second support surface and the second surface, is one step higher than a portion of the sheet, which contacts the first surface, at the upstream in the feed direction.

Accordingly, when the sheets deformed by a curl developed over time or due to moisture are supported on the sheet support surface in a stacked state and the feed roller presses the uppermost sheet downward, the sheet is deformed along the step between the first surface and the second surface, and the second surface reliably contacts the bottom surface of the lowermost sheet.

As a result, the sheet feeder causes the friction member to apply the frictional force to the lowermost sheet with high reliability. This suppresses stacked multi-sheet feed in which sheets are fed in a stacked state, and further suppresses misfeed due to jamming of sheets in a stacked state at the downstream side of the feed roller in the feed direction caused by the stacked multi-sheet feed.

Further, the sheet feeder is likely to be more compact in the height direction, compared to a configuration in which the second surface is not provided and the first surface is located closer to the rotation axis than the second support surface is in the first direction to suppress the stacked multi-sheet feed.

Thus, the sheet feeder of the present disclosure suppresses the stacked multi-sheet feed even when the deformed sheets are supported on the sheet support surface in a stacked state, and realizes reduction in size in the height direction.

DESCRIPTION

As shown in FIG. 1, an image scanning apparatus 1 of an embodiment is an example of one aspect of a sheet feeder of the present disclosure. In FIG. 1, an operation panel 8P side of the image scanning apparatus 1 is a front side. A left side is the side that comes to the left when facing the operation panel 8P. A front-rear direction, a left-right direction, and an upper-lower direction shown in FIG. 2 and the subsequent drawings are all shown in correspondence with the directions shown in FIG. 1.

An overall configuration of the image scanning apparatus 1 will be described. As shown in FIG. 1, the image scanning apparatus 1 includes a main body 8 and a cover 9. The main body 8 is a flat, substantially box-shaped body. The operation panel 8P such as a touch panel is located on a front surface of the main body 8. The main body 8 houses an image forming unit 5 (print engine) in a lower portion thereof. The image forming unit 5 forms an image on a sheet by an inkjet method, a laser method, and so on.

As shown in FIG. 2, the main body 8 houses an image scanner 3 in an upper portion thereof. The image scanner 3 includes a document support surface 3A, a reading surface 3B, an image sensor (reading sensor) 3S, and a scan mechanism (not shown).

The document support surface 3A is an upper surface of a large-area platen glass located on the upper surface of the main body 8. The reading surface 3B is an upper surface of a platen glass that is located on the left side of the document support surface 3A on the upper surface of the main body 8 and extends in the front-rear direction.

The document support surface 3A supports a document to be scanned. The document to be scanned is a sheet such as a paper sheet or an OHP sheet, a book, and so on. The reading surface 3B is used when a conveyance unit 4 described later operates.

The image sensor 3S is a well-known image sensor using a CIS (Contact Image Sensor), a CCD (Charge Coupled Device), and so on, and extends in an elongated shape in the front-rear direction. The image sensor 3S is located below the document support surface 3A and the reading surface 3B.

When the image scanner 3 reads an image of a document supported on the document support surface 3A, the image sensor 3S reads the image of the document in a line shape in the front-rear direction, that is, in a main scanning direction while moving rightward from below the left end of the document support surface 3A, that is, in a sub-scanning direction by an operation of a scan mechanism (not shown). When the image sensor 3S moves to a position below the right end of the document support surface 3A, the image sensor 3S finishes reading (scanning) the image and returns to a standby position by the operation of the scan mechanism (not shown).

When the conveyance unit 4 described later is operated, the image sensor 3S is moved to a stationary reading position below the reading surface 3B by the operation of the scan mechanism (not shown) and is stopped.

As shown in FIG. 1, the cover 9 is located above the main body 8. The rear end of the cover 9 is connected to the rear end of the main body 8 via a hinge (not shown). The cover 9 is swingable about a swing axis X9 extending in the left-right direction.

As shown in FIG. 2, the cover 9 has a base member 39. The lower surface of the base member 39 forms the bottom surface of the cover 9. The bottom surface of the cover 9 has a size capable of covering the document support surface 3A and the reading surface 3B, and covers a document placed on the document support surface 3A.

The base member 39 is an integrally molded product made of a resin material. In the present embodiment, the base member 39 is manufactured by injection molding of a thermoplastic resin and so on.

Although not shown, the user swings the cover 9 upward and rearward about the swing axis X9, whereby the cover 9 opens the document support surface 3A. In this state, the user places a document on the document support surface 3A and takes out the document.

As shown in FIGS. 1 and 2, the cover 9 includes a supply tray 90 and a discharge tray 96. The supply tray 90 and the discharge tray 96 are located at a right portion of the cover 9.

As shown in FIG. 2, an upper surface of a right portion of the base member 39 forms the discharge tray 96. The discharge tray 96 supports a sheet SH that is conveyed and discharged by the conveyance unit 4 described later.

The supply tray 90 is located above the discharge tray 96. The supply tray 90 has a sheet support surface 91. The sheet support surface 91 supports the sheets SH to be scanned, in a stacked state.

In the present embodiment, a target from which an image is read using the document support surface 3A is referred to as a document, and a target from which an image is read while being supported by the sheet support surface 91 and being conveyed by the conveyance unit 4 is referred to as the sheet SH. The document and the sheet SH may be substantially the same.

The sheet support surface 91 extends so as to be gently inclined downward to the left, and extends in the front-rear direction. The width direction of the sheet support surface 91 is the front-rear direction. In the present embodiment, one side in the width direction is the front, and the other side in the width direction is the rear. In the drawings, “one side” means one side in the width direction and “the other side” means the other side in the width direction.

A feed direction DF1 is a direction in which the sheet SH supported on the sheet support surface 91 is fed. The feed direction DF1 is a direction in which the sheet SH is fed along the sheet support surface 91 so as to be gently inclined downward to the left, and is perpendicular to the width direction.

A downstream end 91D of the sheet support surface 91 in the feed direction DF1 is located between a left side surface of the cover 9 and a central portion of the cover 9 in the left-right direction.

As shown in FIGS. 2 and 3, the cover 9 includes an upper chute 34. The upper chute 34 is located above a left portion of the base member 39 and below a left-end-side upper surface cover 98. The upper chute 34 extends in the left-right direction and the width direction. Although not shown, front and rear end portions of the upper chute 34 are assembled to front and rear end portions of the left portion of the base member 39, respectively.

The upper chute 34 integrally includes a first tray 100 and a guide portion 34A. The first tray 100 is a right portion of the upper chute 34. The guide portion 34A is a left portion of the upper chute 34. The first tray 100 extends so as to be gently inclined downward to the left. The guide portion 34A extends so as to be gently inclined upward to the left, and then is curved downward. The upper surface of the guide portion 34A constitutes a conveyance guide surface 34G.

The upper chute 34 is an integrally molded product made of a resin material. In the present embodiment, the upper chute 34 is manufactured by injection molding of a thermoplastic resin and so on.

A specific configuration of the supply tray 90 will be described. The supply tray 90 includes the first tray 100 described above, and a second tray 200 and a sub-tray 300 shown in FIGS. 1 to 3.

The first tray 100 has an upper surface that constitutes a first support surface 101. The first support surface 101 is a part of the sheet support surface 91, and includes a downstream end 91D of the sheet support surface 91.

As shown in FIGS. 4 to 7, the first support surface 101 includes a central portion 101C in the width direction, and portions 101A and 101B located on the outer sides in the width direction with respect to the central portion 101C.

As shown in FIGS. 8 and 9, the central portion 101C of the first support surface 101 is one step higher than the portions 101A and 101B.

As shown in FIG. 7, the angle at which the central portion 101C is inclined downward to the left changes in a plurality of stages. The angle at which the portions 101A and 101B are inclined downward to the left also changes in a plurality of stages along the central portion 101C.

As will be described in detail later, a friction member (friction sheet) 70 is affixed to the central portion 101C.

As shown in FIGS. 2 and 3, the second tray 200 is located on the right side of the first tray 100. The second tray 200 extends so as to be gently inclined downward toward the left, and extends in the width direction. Although not shown, front and rear end portions of the second tray 200 are assembled to the front and rear end portions of the left portion of the base member 39, respectively, at positions further rightward than the first tray 100.

The second tray 200 is an integrally molded product made of a resin material. In the present embodiment, the second tray 200 is manufactured by injection molding of a thermoplastic resin and so on.

As shown in FIG. 3, a central portion of the upper surface of the second tray 200 in the width direction constitutes a second support surface 201. The second support surface 201 is a flat surface that is one step higher than portions 201A and 201B located on the outer sides in the width direction with respect to the second support surface 201.

The second support surface 201 is a part of a remaining portion of the sheet support surface 91. The second support surface 201 is adjacent to the first support surface 101 from upstream in the feed direction DF1. As shown in FIG. 2, an upstream end and a downstream end of the second support surface 201 in the feed direction DF1 are gently curved to prevent the sheet SH from being caught by the edges of the second support surface 201.

As shown in FIG. 3, the second tray 200 supports a pair of side guides 92A and 92B at the portions 201A and 201B.

Each side guide 92A, 92B is of generally identical construction, with mirror image, and includes a guide wall 92W and a sheet edge support portion 92C.

The sheet edge support portion 92C of the front side guide 92A is slidable in the width direction on the portion 201A. The sheet edge support portion 92C of the rear side guide 92B is slidable in the width direction on the portion 201B.

The upper surface of the sheet edge support portion 92C of each side guide 92A, 92B is designed to be a flat surface that is flush with the second support surface 201. Note that the upper surface of the sheet edge support portion 92C may be slightly shifted from a state of being flush with the second support surface 201 due to manufacturing errors, looseness at the time of assembly, and so on.

The guide wall 92W of the side guide 92A is connected to the front end of the sheet edge support portion 92C of the side guide 92A, protrudes upward, and extends in the left-right direction. The guide wall 92W of the side guide 92B is connected to the rear end of the sheet edge support portion 92C of the side guide 92B, protrudes upward, and extends in the left-right direction.

The side guides 92A and 92B are coupled to each other by an interlocking mechanism 93 shown in FIG. 2. The interlocking mechanism 93 is a well-known rack and pinion mechanism, and causes the side guides 92A and 92B to move toward and away from each other in the width direction.

As shown in FIG. 1, the side guides 92A and 92B are configured to position the sheets SH of various sizes supported on the sheet support surface 91 by sandwiching the sheets SH in the width direction by the respective guide walls 92W.

At this time, the sheet edge support portion 92C of the side guide 92A supports, from below, the edge of the sheet SH located on one side in the width direction. The sheet edge support portion 92C of the side guide 92B supports, from below, the edge of the sheet SH located on the other side in the width direction.

In the present embodiment, the sheets SH as image scan targets include postcards, A5 to A4 size sheets, and so on.

As shown in FIGS. 2 and 3, the sub tray 300 is located on the right side of the second tray 200, and is connected to front and rear end portions (not shown) of the second tray 200. The sub-tray 300 has an upper surface that serves as a third support surface 301.

The third support surface 301 is adjacent to the second support surface 201 from upstream in the feed direction DF1. The third support surface 301 is a remaining portion of the sheet support surface 91 excluding the first support surface 101 and the second support surface 201.

The conveyance unit 4 and first, second, and third conveyance guides will be described. As shown in FIG. 2, the cover 9 includes the conveyance unit 4, a first conveyance guide 31, a second conveyance guide 32, and a third conveyance guide 33. The conveyance unit 4, the first conveyance guide 31, the second conveyance guide 32, and the third conveyance guide 33 are located inside the left portion of the cover 9.

The conveyance unit 4 includes a feed roller 41, a separation roller 42, a separation pad 42A, a holder arm 50, a first conveyance roller pair 43, a pressing member 44, a second conveyance roller pair 45, a discharge roller 47, and an elastic piece 48.

The feed roller 41 is located upstream of the downstream end 91D of the sheet support surface 91 in the feed direction DF1, and faces the central portion 101C of the first support surface 101 from above.

The separation roller 42 is located downstream of the downstream end 91D of the sheet support surface 91 in the feed direction DF1, and faces the conveyance guide surface 34G from above. The separation roller 42 is assembled to a drive shaft 42S having a drive axis X42 extending in the width direction as a center.

The separation pad 42A is swingably supported by the guide portion 34A in a state where the separation pad 42A is exposed on the conveyance guide surface 34G and faces the separation roller 42 from below. The separation pad 42A is pressed toward the separation roller 42 by a spring.

Although not shown, the drive shaft 42S is inserted through the holder arm 50. The holder arm 50 extends farther rightward than the drive axis X42, and supports the feed roller 41 at a right end portion thereof such that the feed roller 41 is rotatable about a rotation axis X41 extending in the width direction.

A torque limiter (not shown) is interposed between the holder arm 50 and the drive shaft 42S. The holder arm 50 supports a gear train (not shown) that transmits a drive force from the drive shaft 42S to the feed roller 41.

The drive shaft 42S rotates about the drive axis X42 by a drive force of a drive source (not shown) being transmitted thereto. The drive source is a motor, for example.

When the drive source (not shown) rotates in the forward direction, the torque limiter (not shown) causes the holder arm 50 to rotate following the rotation of the drive shaft 42S. Thus, the holder arm 50 swings to lower the feed roller 41. When the feed roller 41 contacts a top surface SH1 of the uppermost sheet SH supported on the sheet support surface 91, the torque limiter (not shown) causes a slip therein to hold the holder arm 50 at that position. As a result, the feed roller 41 presses the sheets SH supported on the sheet support surface 91 downward.

In this case, the drive shaft 42S transmits a drive force to the separation roller 42 to rotate the separation roller 42 about the drive axis X42, and transmits a drive force to the feed roller 41 via a gear train (not shown) to rotate the feed roller 41. The feed roller 41 feeds the uppermost sheet SH supported on the sheet support surface 91 in the feed direction DF1. The separation roller 42 and the separation pad 42A separate the sheets SH one sheet at a time and convey the sheets SH when the sheets SH fed by the feed roller 41 are plural.

When the drive source (not shown) rotates in the reverse direction, the torque limiter (not shown) causes the holder arm 50 to rotate following the rotation of the drive shaft 42S in the reverse direction. Thus, the holder arm 50 swings to raise the feed roller 41.

The position of the feed roller 41 (41U) shown in FIGS. 2 and 6 to 8 is an upper limit position. The rotation axis X41 of the feed roller 41 (41U) at the upper limit position is referred to as a rotation axis X41U. When the feed roller 41 reaches the upper limit position, the torque limiter (not shown) causes a slip therein to hold the holder arm 50 at the position.

In this state, since the rotation of the separation roller 42 and the feed roller 41 is useless, a controller (not shown) stops the drive source (not shown) immediately when the feed roller 41 reaches the upper limit position. The torque limiter (not shown) holds the holder arm 50 at the position even after the drive source (not shown) is stopped.

The feed roller 41 is configured to contact a first surface 71 of the friction member 70 described later when there is no sheet SH supported on the sheet support surface 91. The position of the feed roller 41 (41D) shown in FIGS. 2, 6, and 7 is a lower limit position at which the feed roller 41 contacts the first surface 71 of the friction member 70 described later. The rotation axis X41 of the feed roller 41 (41D) at the lower limit position is referred to as a rotation axis X41D.

As shown in FIG. 2, the first conveyance roller pair 43 is located on the left side wall of the cover 9 and on the side close to the upper surface of the main body 8. The pressing member 44 is located directly above the reading surface 3B.

The first conveyance guide 31 is formed of the conveyance guide surface 34G, ribs protruding downward from the bottom surface of the left-end-side upper surface cover 98, and so on. The first conveyance guide 31 guides the sheet SH supported on the sheet support surface 91 to the first conveyance roller pair 43.

The second conveyance guide 32 is formed of a part of a chute member located below the guide portion 34A of the upper chute 34 in the cover 9, a guide surface formed inside the left side surface of the cover 9, and so on.

The second conveyance guide 32 guides the sheet SH from the first conveyance roller pair 43 to the reading surface 3B in a downwardly inclined manner, and then guides the sheet SH to pass between the pressing member 44 and the reading surface 3B, that is, to pass above the image sensor 3S at the stationary reading position.

The second conveyance roller pair 45 is located at a position separated upward and leftward from the left end of the discharge tray 96. The discharge roller 47 is located at a position separated upward from the left end of the discharge tray 96 and slightly shifted leftward from the left end of the discharge tray 96. The upper end of the discharge roller 47 is located above a nip position of the second conveyance roller pair 45.

The elastic piece 48 is made of a film having high rigidity. The elastic piece 48 is cantilevered between the second conveyance roller pair 45 and the discharge roller 47, protrudes rightward, and is bent at a position rightward of the discharge roller 47 to be inclined downward to the right.

Although not shown, the conveyance unit 4 includes a plurality of discharge rollers 47 and a plurality of elastic pieces 48, and the discharge rollers 47 and the elastic pieces 48 are alternately arranged in the width direction. For simplicity, the plurality of discharge rollers 47 are referred to as the discharge roller 47, and the plurality of elastic pieces 48 are referred to as the elastic piece 48 in this specification.

The third conveyance guide 33 is formed of a lower surface of a chute member located below the first tray 100 and the second tray 200 inside the cover 9, an upward-facing conveyance guide surface of the base member 39 formed between the reading surface 3B and the discharge tray 96, and so on.

The third conveyance guide 33 guides the sheet SH to be inclined upward to the right at a position on the right side of the reading surface 3B to cause the sheet SH to pass through the second conveyance roller pair 45, and further guides the sheet SH to the discharge roller 47 and the elastic piece 48.

As shown in FIG. 2, the image scanning apparatus 1 includes the friction member 70. The friction member 70 is provided at a position facing the feed roller 41 on the sheet support surface 91, more specifically, on the first support surface 101.

The friction member 70 is configured to contact a bottom surface SH2 of the lowermost sheet SH supported on the sheet support surface 91 and apply a frictional force to the lowermost sheet SH. Thus, the friction member 70 is made of a material, such as cork, rubber, or elastomer, which applies a larger frictional force to the sheet SH than the resin material of the first tray 100.

As shown in FIGS. 4 to 7, in the present embodiment, the friction member 70 is a cork sheet that is approximately 61 mm in the width direction, approximately 20 mm in the feed direction DF1, and approximately 1 mm thick. The friction member 70 is affixed to the central portion 101C of the first support surface 101 by a double-sided tape and so on.

As shown in FIG. 5, in this embodiment, a dimension W41 of the feed roller 41 in the width direction is approximately 27 mm. The dimension (approximately 61 mm) of the friction member 70 in the width direction is greater than or equal to twice the dimension W41 and is less than or equal to three times of the dimension W41.

As shown in FIG. 7, the friction member 70 has the first surface 71, a second surface 72, a third surface 73, and a fourth surface 74. The third surface 73, the second surface 72, the fourth surface 74, and the first surface 71 are continuously arranged in this order along the feed direction DF1, thereby forming a top surface of the friction member 70.

In other words, one friction member 70 having the third surface 73, the second surface 72, the fourth surface 74, and the first surface 71 which are continuous along the feed direction DF1 is provided at the first tray 100.

As shown in FIG. 5, a dimension W71 of the first surface 71 in the width direction and a dimension W72 of the second surface 72 in the width direction are equal to the dimension (approximately 61 mm) of the friction member 70 in the width direction. The dimension of the third surface 73 in the width direction and the dimension of the fourth surface 74 in the width direction are also equal to the dimension of the friction member 70 in the width direction.

As shown in FIG. 7, the first surface 71 is provided at a position facing the feed roller 41 in the central portion 101C of the first support surface 101. The first surface 71 is configured to contact the feed roller 41 when there is no sheet SH supported on the sheet support surface 91. More specifically, the first surface 71 contacts the feed roller 41 (41D) which is lowered to the lower limit position when there is no sheet SH supported on the sheet support surface 91.

As viewed in the width direction, a perpendicular line PL1 is defined as a perpendicular line that is drawn from the rotation axis X41 (X41D) to the first surface 71 in a state where the feed roller 41 (41D) at the lower limit position contacts the first surface 71. The perpendicular line PL1 is inclined so as to be separated from the vertical direction toward upstream in the feed direction DF1 as the perpendicular line PL1 goes downward. A direction parallel to the perpendicular line PL1 is defined as a first direction D1. An extension line of the second support surface 201 as viewed in the width direction is defined as an extension line EL1.

The first surface 71 is located farther from the rotation axis X41 than the second support surface 201 and the second surface 72 are in the first direction D1. That is, as viewed in the width direction, a distance between the rotation axis X41 and the first surface 71 in the first direction D1 is greater than a distance between the rotation axis X41 and the second support surface 201 in the first direction D1. Further, as viewed in the width direction, a distance between the rotation axis X41 and the first surface 71 in the first direction D1 is greater than a distance between the rotation axis X41 and the second surface 72 in the first direction D1. The first surface 71 is located closer to the rotation axis X41 than the first support surface 101 (101A, 101B, 101C) is in the first direction D1. The first surface 71 is located farther downstream in the feed direction DF1 than an upstream end 41V of the feed roller 41 (41D) which is lowered to the lower limit position and contacts the first surface 71.

The first surface 71 includes a first flat surface 71F. The first flat surface 71F is a flat surface parallel to the second support surface 201.

As shown in FIGS. 4 and 5, the portions 101A and 101B include portions 101A1 and 101B1, respectively, which are located outward of the first surface 71 in the width direction.

As shown in FIG. 7, the first flat surface 71F is parallel to the portions 101A1 and 101B1.

The second surface 72 is provided upstream of the first surface 71 in the feed direction DF1 in the central portion 101C of the first support surface 101. The second surface 72 is located farther upstream in the feed direction DF1 than the upstream end 41V of the feed roller 41 (41D) which is lowered to the lower limit position and contacts the first surface 71.

The second surface 72 includes a second flat surface 72F. The second flat surface 72F is a flat surface parallel to the second support surface 201. The second flat surface 72F is designed to be flush with the second support surface 201. That is, the second surface 72 is located at the same position as the second support surface 201 in the first direction D1. The second flat surface 72F may be slightly shifted from a state of being flush with the second support surface 201 due to manufacturing errors, looseness at the time of assembly, and so on.

The third surface 73 is provided upstream of the second surface 72 in the feed direction DF1 in the central portion 101C of the first support surface 101. The third surface 73 is connected to an upstream end 72U of the second surface 72 in the feed direction DF1.

The third surface 73 is inclined so as to be separated from the second support surface 201 toward the opposite side of the rotation axis X41 in the first direction D1 as the third surface 73 extends toward upstream in the feed direction DF1. In the present embodiment, as viewed in the width direction, an angle a formed by the third surface 73 and the extension line EL1 is greater than or equal to 10 degrees and less than or equal to 12 degrees.

The fourth surface 74 is connected to an upstream end 71U of the first surface 71 in the feed direction DF1 and a downstream end 72D of the second surface 72 in the feed direction DF1. The fourth surface 74 is inclined so as to be separated from the second support surface 201 to the opposite side of the rotation axis X41 in the first direction D1 as the fourth surface 74 extends toward downstream in the feed direction DF1.

As shown in FIGS. 4 and 5, the first tray 100 includes a protrusion 130. The protrusion 130 is formed at a portion of the first tray 100 that is located upstream of the central portion 101C of the first support surface 101 in the feed direction DF1.

As shown in FIG. 5, the protrusion 130 extends in the width direction along an upstream end 73U of the third surface 73 in the feed direction DF1.

As shown in FIG. 7, the protrusion 130 protrudes so as to approach the second support surface 201 (the extension line EL1) in the first direction D1. An apex 131 of the protrusion 130 is located between the upstream end 73U of the third surface 73 and the second support surface 201 in the first direction D1.

The protrusion 130 includes an inclined surface 132. The inclined surface 132 is a curved surface that is inclined so as to be separated from the second support surface 201 toward the opposite side of the rotation axis X41 in the first direction D1 as the inclined surface 132 extends from the apex 131 toward upstream in the feed direction DF1.

As shown in FIGS. 5 and 7, the central portion 101C of the first support surface 101 includes an affix surface 113. A portion of the friction member 70 having the third surface 73 is affixed to the affix surface 113.

The protrusion 130 includes an abutment surface 133. The abutment surface 133 is a flat surface extending from the apex 131 to an upstream end of the affix surface 113 in the feed direction DF1 and extending in the width direction. The abutment surface 133 abuts on the upstream end 73U of the third surface 73 from upstream in the feed direction DF1.

As shown in FIGS. 4 and 5, the first tray 100 includes positioning ribs 139A and 139B. The front positioning rib 139A is connected to the front end of the protrusion 130 and extends in the feed direction DF1. The rear positioning rib 139B is connected to the rear end of the protrusion 130 and extends in the feed direction DF1. The affix surface 113 is located between the positioning ribs 139A and 139B in the width direction. The height of the positioning ribs 139A and 139B protruding upward is smaller than the thickness of the friction member 70.

An operator who affixes the friction member 70 to the central portion 101C of the first support surface 101 positions the portion of the friction member 70 having the third surface 73 between the positioning rib 139A and the positioning rib 139B, and causes the upstream end 73U of the third surface 73 to abut against the abutment surface 133. This allows the operator to accurately position and affix the portion of the friction member 70 having the third surface 73 with respect to the affix surface 113 in the width direction and the feed direction DF1.

The operations and effects of the first surface 71 to the fourth surface 74 will be described. As shown in FIG. 6, the first surface 71 is configured to contact the bottom surface SH2 of the lowermost sheet SH supported on the sheet support surface 91. Whether the first surface 71 contacts the bottom surface SH2 of the lowermost sheet SH supported on the sheet support surface 91 is determined by the degree of deformation of the sheet SH caused by a curl of the sheet SH developed over time or due to moisture.

For example, when the sheets SH, which are thin and have low rigidity, are supported on the sheet support surface 91 in a stacked state, the sheets SH are bent by their own weight so as to follow the sheet support surface 91. As a result, the first surface 71 contacts the bottom surface SH2 of the lowermost sheet SH supported on the sheet support surface 91.

As shown in FIG. 8, when the sheets SH which are deformed by a curl developed over time or due to moisture are supported on the sheet support surface 91 in a stacked state, there is a possibility that the sheets SH are curved such that the central portion of the sheets SH in the width direction is lifted from the sheet support surface 91. As a result, the first surface 71 is less likely to contact the bottom surface SH2 of the lowermost sheet SH supported on the sheet support surface 91. In particular, the central portion of the first surface 71 in the width direction is less likely to contact the bottom surface SH2 of the lowermost sheet SH than the outer edges of the first surface 71 in the width direction.

As shown in FIG. 9, in a case where the deformed sheets SH are supported on the sheet support surface 91 in a stacked state, when a drive force is transmitted from the drive source (not shown) rotating in the forward direction to the drive shaft 42S and the feed roller 41 is lowered from the upper limit position, the feed roller 41 presses the uppermost sheet SH supported on the sheet support surface 91 downward. Thereby, the central portion in the width direction of the deformed sheets SH is pressed down, and the deformed sheets SH are corrected into a substantially M-shape. As a result, if the degree of deformation of the sheets SH is not excessive, the first surface 71 is likely to contact the bottom surface SH2 of the lowermost sheet SH supported on the sheet support surface 91. If the degree of deformation of the sheets SH is excessive, the central portion of the first surface 71 in the width direction remains unlikely to contact the bottom surface SH2 of the lowermost sheet SH, but the outer edges of the first surface 71 in the width direction are likely to contact the bottom surface SH2 of the lowermost sheet SH.

As shown in FIG. 6, the second surface 72 contacts the bottom surface SH2 of the lowermost sheet SH supported on the sheet support surface 91. In particular, in a case where the sheets SH deformed by a curl developed over time or due to moisture are supported on the sheet support surface 91 in a stacked state, when the feed roller 41 lowered from the upper limit position presses the uppermost sheet SH supported on the sheet support surface 91 downward, the sheets SH are deformed along the step between the first surface 71 and the second surface 72, and the second surface 72 reliably contacts the bottom surface SH2 of the lowermost sheet SH.

The third surface 73 is configured to contact the bottom surface SH2 of the lowermost sheet SH mainly when the user places the sheets SH on the sheet support surface 91. At this time, the third surface 73 guides the leading end of the sheet SH that are being inserted along the second support surface 201 toward the second surface 72. Since the third surface 73 and the second surface 72 are continuous, the sheet SH passes the second surface 72 without being caught by the upstream end 72U of the second surface 72.

The fourth surface 74 is configured to contact the bottom surface SH2 of the lowermost sheet SH supported on the sheet support surface 91. Whether the fourth surface 74 contacts the bottom surface SH2 of the lowermost sheet SH supported on the sheet support surface 91 is determined by the degree of deformation of the sheet SH caused by the sheet SH a curl developed over time or due to moisture. Since the fourth surface 74 and the first surface 71 are continuous, even if the leading end of the sheet SH is curled downward, the sheet SH passes the first surface 71 without being caught by the upstream end 71U of the first surface 71.

An image scanning operation of a document supported on the sheet support surface 91 will be described. In the image scanning apparatus 1, when the image scanner 3 scans an image of the sheet SH supported on the sheet support surface 91, the controller (not shown) drives the drive source (not shown) to rotate in the forward direction to operate the conveyance unit 4.

In the conveyance unit 4, the feed roller 41 and the separation roller 42 are rotationally driven in the clockwise direction in FIG. 2, a drive roller 43A of the first conveyance roller pair 43 and a drive roller 45A of the second conveyance roller pair 45 are rotationally driven in the counterclockwise direction in FIG. 2, and the discharge roller 47 is rotationally driven in the clockwise direction in FIG. 2.

With this operation, the holder arm 50 swings to lower the feed roller 41 (41U) located at the upper limit position, and the feed roller 41 contacts the top surface SHI of the uppermost sheet SH supported on the sheet support surface 91. At this time, the feed roller 41 presses the uppermost sheet SH supported on the sheet support surface 91 downward.

The feed roller 41 feeds the uppermost sheet SH supported on the sheet support surface 91 in the feed direction DF1. At this time, at least the second surface 72 among the first surface 71 to the fourth surface 74 of the friction member 70 contacts the bottom surface SH2 of the lowermost sheet SH supported on the sheet support surface 91 and applies a frictional force to the lowermost sheet SH. As a result, the image scanning apparatus 1 suppresses stacked multi-sheet feed in which the multiple sheets SH are fed in a stacked state. Thus, the image scanning apparatus 1 suppresses misfeed caused by the sheets SH being jammed in a stacked state in a conveyance space which is narrowed downstream of the feed roller 41 in the feed direction DF1 and upstream of the separation roller 42 in the feed direction DF1 due to the stacked multi-sheet feed.

When the sheets SH fed by the feed roller 41 are a plurality of sheets, the separation roller 42 and the separation pad 42A separate the sheets SH one sheet at a time and convey the sheet SH toward the first conveyance roller pair 43.

Next, the first conveyance roller pair 43 conveys the sheet SH guided by the first conveyance guide 31 and the second conveyance guide 32 to cause the sheet SH to pass above the image sensor 3S at the stationary reading position. Thus, the image sensor 3S reads the image of the sheet SH.

Thereafter, the second conveyance roller pair 45 conveys the sheet SH guided by the third conveyance guide 33 toward the discharge roller 47 and the elastic piece 48. The discharge roller 47 and the elastic piece 48 discharge the sheet SH to the discharge tray 96 while deforming the sheet SH into a wave shape.

At this time, the discharge roller 47 and the elastic piece 48 discharge the sheet SH to the discharge tray 96 from a position higher than the nip position of the second conveyance roller pair 45

When the image scanning operation of the sheet SH is finished, the controller (not shown) reversely rotates the drive source (not shown) for a short time. With this operation, the holder arm 50 swings so as to raise the feed roller 41 to the upper limit position. As a result, the feed roller 41 (41U) moved to the upper limit position is in a state of being separated upward from the uppermost sheet SH supported on the sheet support surface 91.

In the image scanning apparatus 1 of the embodiment, as shown in FIG. 7, the second support surface 201 of the second tray 200 and the second surface 72 of the friction member 70 are located upstream of the first surface 71 of the friction member 70 in the feed direction DF1. The first surface 71 is located farther from the rotation axis X41 than the second support surface 201 and the second surface 72 are in the first direction D1.

That is, the portion of the sheet SH supported on the sheet support surface 91 that contacts the second support surface 201 and the second surface 72 is one step higher than the portion of the sheet SH that contacts the first surface 71 at a position upstream in the feed direction DF1.

Accordingly, as shown in FIGS. 8 and 9, when the sheets SH which are deformed by a curl developed over time or due to moisture are stacked on the sheet support surface 91, and the feed roller 41 presses the uppermost sheet SH downward, as shown in FIG. 6, the sheet SH is deformed along the step between the first surface 71 and the second surface 72, and the second surface 72 reliably contacts the bottom surface SH2 of the lowermost sheet SH.

As a result, in the image scanning apparatus 1, a frictional force is reliably applied to the lowermost sheet SH by the friction member 70. This suppresses stacked multi-sheet feed in which the sheets SH are fed in a stacked state, and further suppresses misfeed caused by the sheets SH being jammed in a stacked state in the conveyance space which is narrowed downstream of the feed roller 41 in the feed direction DF1 and upstream of the separation roller 42 in the feed direction DF1, which is caused by the stacked multi-sheet feed.

In the image scanning apparatus 1, the size in the height direction is likely to be reduced, compared to a configuration in which the second surface 72 is not provided and the first surface 71 is located closer to the rotation axis X41 than the second support surface 201 is in the first direction D1 for suppressing multi-sheet feed.

In the image scanning apparatus 1, the size in the height direction is likely to be reduced, compared to a configuration in which a pressing mechanism is added between a right end portion of the holder arm 50 and the bottom surface of the left-end-side upper surface cover 98 for improving the ability to correct the deformed sheets SH.

Thus, the image scanning apparatus 1 of the embodiment suppresses the stacked multi-sheet feed of the sheets SH even when the deformed sheets SH are supported on the sheet support surface 91 in a stacked state, and realizes reduction of the size in the height direction.

In the image scanning apparatus 1, the first surface 71 is one step lower than the second support surface 201 and the second surface 72, which reduces the frictional force that is received when the leading end of the sheet SH inserted along the second support surface 201 contacts the first surface 71. As a result, in the image scanning apparatus 1, the leading end of the sheet SH is smoothly inserted to the downstream end 91D of the sheet support surface 91.

In the image scanning apparatus 1, as shown in FIG. 7, the second surface 72 is located farther upstream in the feed direction DF1 than the upstream end 41V in the feed direction DF1 of the feed roller 41 (41D) which is lowered to the lower limit position and contacts the first surface 71. With this configuration, when the deformed sheets SH are supported on the sheet support surface 91 in a stacked state, the sheets SH are deformed with high reliability along the step between the first surface 71 and the second surface 72, and thus the second surface 72 contacts the bottom surface SH2 of the lowermost sheet SH with higher reliability. As a result, in the image scanning apparatus 1, the friction member 70 applies the frictional force to the lowermost sheet SH with higher reliability, which suppresses the stacked multi-sheet feed and further suppresses misfeed caused by the stacked multi-sheet feed.

In the image scanning apparatus 1, the third surface 73 is connected to the upstream end 72U of the second surface 72 in the feed direction DF1, and is inclined so as to be separated from the second support surface 201 to the opposite side of the rotation axis X41 in the first direction D1 toward upstream in the feed direction DF1. With this configuration, the third surface 73 guides the leading end of the sheet SH that is inserted along the second support surface 201 toward the second surface 72. Since the third surface 73 and the second surface 72 are continuous, the sheet SH passes the second surface 72 without being caught by the upstream end 72U of the second surface 72. As a result, in the image scanning apparatus 1, the leading end of the sheet SH is smoothly inserted to the downstream end 91D of the sheet support surface 91.

In the image scanning apparatus 1, the apex 131 of the protrusion 130 is located between the upstream end 73U of the third surface 73 and the second support surface 201 in the first direction D1. The inclined surface 132 of the protrusion 130 is a curved surface that is inclined so as to be separated from the second support surface 201 toward the opposite side of the rotation axis X41 in the first direction D1 as the inclined surface 132 extends from the apex 131 toward upstream in the feed direction DF1. With this configuration, the inclined surface 132 and the apex 131 guide the leading end of the sheet SH inserted along the second support surface 201 to a position above the upstream end 73U of the third surface 73. Thus, the sheet SH passes the third surface 73 without being caught by the third surface 73. As a result, in the image scanning apparatus 1, the leading end of the sheet SH is smoothly inserted to the downstream end 91D of the sheet support surface 91. Further, this configuration suppresses the inserted sheet SH applying a force that peels the friction member 70 from the first tray 100 to the upstream end 73U of the third surface 73 of the friction member 70.

In the image scanning apparatus 1, as shown in FIGS. 5 and 7, the first tray 100 includes the affix surface 113 to which the portion of the friction member 70 having the third surface 73 is affixed. The protrusion 130 includes the abutment surface 133 that abuts against the upstream end 73U of the third surface 73 from upstream in the feed direction DF1. This configuration allows the operator who affixes the friction member 70 to the central portion 101C of the first support surface 101 to accurately position the portion of the friction member 70 having the third surface 73 with respect to the affix surface 113 by abutting the upstream end 73U of the third surface 73 against the abutment surface 133.

In the image scanning apparatus 1, as shown in FIG. 7, the friction member 70 includes the fourth surface 74 which is connected to the upstream end 71U of the first surface 71 in the feed direction DF1 and the downstream end 72D of the second surface 72 in the feed direction DF1 and which is configured to contact the bottom surface SH2 of the lowermost sheet SH. The single friction member 70 including the third surface 73, the second surface 72, the fourth surface 74, and the first surface 71 which are continuous along the feed direction DF1 is provided on the first tray 100. With this configuration, the leading end of the sheet SH inserted along the second support surface 201 is less likely to be caught by the third surface 73, the second surface 72, the fourth surface 74, and the first surface 71 that are continuous with each other. As a result, in the image scanning apparatus 1, the leading end of the sheet SH is smoothly inserted to the downstream end 91D of the sheet support surface 91. Further, with this configuration, the friction member 70 has a large contact surface with the bottom surface SH2 of the lowermost sheet SH, and thus the frictional force is applied to the lowermost sheet SH with higher reliability. Further, compared to a case where the friction member 70 is formed of a plurality of friction members, this configuration suppresses a problem in which end edges of the friction member 70 are scraped by sliding contact with the sheet SH.

In the image scanning apparatus 1, the second surface 72 is located at the same position as the second support surface 201 in the first direction D1. With this configuration, when the deformed sheets SH are supported on the sheet support surface 91 in a stacked state, the sheets SH are deformed with high reliability along the step between the first surface 71 and the second surface 72, and thus the second surface 72 reliably contacts the bottom surface SH2 of the lowermost sheet SH. As a result, in the image scanning apparatus, the friction member 70 applies the frictional force to the lowermost sheet SH with higher reliability, which suppresses stacked multi-sheet feed and suppresses misfeed caused by the stacked multi-sheet feed.

In the image scanning apparatus 1, the first surface 71 includes the first flat surface 71F that is parallel to the portions 101A1 and 101B1 of the first support surface 101 located outside the first surface 71 in the width direction. The second surface 72 includes the second flat surface 72F that is parallel to the second support surface 201. With this configuration, the first flat surface 71F of the first surface 71 and the second flat surface 72F of the second surface 72 are less likely to interfere with the leading end of the sheet SH inserted along the second support surface 201. Further, the friction member 70 has a large contact surface with the bottom surface SH2 of the lowermost sheet SH, and thus the frictional force is applied to the lowermost sheet SH with higher reliability.

In the image scanning apparatus 1, as shown in FIG. 5, each of the dimension W71 of the first surface 71 in the width direction and the dimension W72 of the second surface 72 in the width direction is equal to the dimension (approximately 61 mm) of the friction member 70 in the width direction, and is greater than or equal to twice the dimension W41 (approximately 27 mm) of the feed roller 41 in the width direction and is less than or equal to three times of the dimension W41. With this configuration, when the deformed sheets SH are supported on the sheet support surface 91 in a stacked state, the outer edges of the first surface 71 in the width direction are likely to contact the bottom surface SH2 of the lowermost sheet SH, and the second surface 72 reliably contacts the bottom surface SH2 of the lowermost sheet SH. As a result, in the image scanning apparatus 1, the friction member 70 applies the frictional force to the lowermost sheet SH with higher reliability, which suppresses stacked multi-sheet feed and suppress misfeed caused by the stacked multi-sheet feed. Further, this configuration suppresses an increase in material cost of the friction member 70.

In the image scanning apparatus 1, as shown in FIG. 7, the first surface 71 is located closer to the rotation axis X41 than the first support surface 101 (101A, 101B, 101C) is in the first direction D1. With this configuration, the first surface 71 is more likely to contact the bottom surface SH2 of the lowermost sheet SH than the first support surface 101 is. Thus, when the deformed sheets SH are supported on the sheet support surface 91 in a stacked state, the first surface 71 is more likely to contact the bottom surface SH2 of the lowermost sheet SH.

While the present disclosure has been described in conjunction with various example structures outlined above and illustrated in the figures, various alternatives, modifications, variations, improvements, and/or substantial equivalents, whether known or that may be presently unforeseen, may become apparent to those having at least ordinary skill in the art. Accordingly, the example embodiments of the disclosure, as set forth above, are intended to be illustrative of the disclosure, and not limiting the disclosure. Various changes may be made without departing from the spirit and scope of the disclosure. Thus, the disclosure is intended to embrace all known or later developed alternatives, modifications, variations, improvements, and/or substantial equivalents. Some specific examples of potential alternatives, modifications, or variations in the described disclosure are provided below.

In the embodiment, the number of the friction member 70 is one. However, the present disclosure also includes a configuration in which a plurality of friction members are provided as in a modification shown in FIG. 10.

In the image scanning apparatus of the modification, the friction member 70 according to the embodiment is divided into two friction members 70A and 70B.

The friction member 70A corresponds to a portion of the friction member 70 having the second surface 72 and the third surface 73. The configurations of the second surface 72 and the third surface 73 are the same as those in the embodiment. The friction member 70A is provided separately from the friction member 70B and located upstream of the friction member 70B in the feed direction DF1.

The friction member 70B corresponds to a portion of the friction member 70 having the first surface 71 and the fourth surface 74 in which a fifth surface 75 is provided instead of the fourth surface 74. The configuration of the first surface 71 is the same as that of the embodiment.

The fifth surface 75 is connected to the upstream end 71U of the first surface 71 in the feed direction DF1. The fifth surface 75 is inclined so as to be separated from the first surface 71 to the opposite side of the rotation axis X41 in the first direction D1 toward upstream in the feed direction DF1. With this configuration, the fifth surface 75 guides the leading end of the sheet SH inserted along the second surface 72 toward the first surface 71.

The shape of the central portion 101C of the first support surface 101 is changed to have a portion recessed in accordance with the fifth surface 75.

The image scanning apparatus of the modification having such a configuration suppresses stacked multi-sheet feed of the sheets SH even when the deformed sheets SH are supported on the sheet support surface 91 in a stacked state, and realizes reduction in size in the height direction, similarly to the image scanning apparatus 1 of the embodiment.

In the embodiment, the sheet feeder of the present disclosure is embodied as the image scanning apparatus 1 having an image scanning function and an image forming function (print function), but the present disclosure is not limited to this configuration. For example, the configuration of the present disclosure may be applied to an image scanning apparatus having the image scanning function, or the configuration of the present disclosure may be applied to an image forming apparatus having the image forming function.

In the embodiment, the second surface 72 is located at the same position as the second support surface 201 in the first direction D1, but the present disclosure is not limited to this configuration. For example, the present disclosure includes a configuration in which the second surface 72 is located at a position closer to the rotation axis X41 than the second support surface 201 is, and a configuration in which the second surface 72 is located at a position farther from the rotation axis X41 than the second support surface 201 is.

In the embodiment, the abutment surface 133 is one flat surface, but the present disclosure is not limited to this configuration. For example, the abutment surface may be a plurality of protrusions.