Sheet feeding device

Abstract

The present invention provides a sheet feeding device that can suppress double feeding of sheets even when deformed sheets are supported on a support surface in a stacked state. [Solution] In the sheet feeding device 1, the first guide surface 61 is located downstream of the support surface 95 in the feeding direction DF1. The second guide surface 62 is located downstream of the support surface 95 in the feeding direction DF1 and is aligned with the first guide surface 61 in the width direction, guiding a portion of the sheet SH in the width direction so as to be lifted away from the first guide surface 61. The friction member 70 has a first portion 71 provided on the support surface 95 and facing the feeding roller 41 from below, which applies a frictional force to the sheet SH supported by the support surface 95, and a second portion 72 provided on the first guide surface 61 and aligned with the second guide surface 62 in the width direction, with a portion including the downstream end 72D in the feeding direction DF1 located below the second guide surface 62, which is capable of applying a frictional force to the sheet SH guided by the first guide surface 61 and the second guide surface 62.

Description

TECHNICAL FIELD

[0001] The present invention relates to a sheet feeding apparatus. BACKGROUND ART

[0002] Patent Document 1 discloses a document conveying apparatus which is an example of a conventional sheet feeding apparatus. As shown in FIG. 6 thereof, this document conveying apparatus includes a document placement portion, a pickup roller, and a friction member.

[0003] The document placement portion supports sheets in a stacked state. The pickup roller feeds a sheet supported by the document placement portion in a feeding direction perpendicular to the width direction of the document placement portion.

[0004] The friction member is formed of a cork sheet or the like. The friction member is provided on the document placement portion and faces the pickup roller from below. The friction member applies a frictional force to sheets supported by the document placement portion, thereby suppressing a problem that sheets are fed in an overlapped manner during feeding. PRIOR ART DOCUMENTS PATENT DOCUMENTS

[0005] Patent Document 1 Japanese Unexamined Patent Publication No. 2020-111460 SUMMARY OF THE INVENTION PROBLEM TO BE SOLVED BY THE INVENTION

[0006] Incidentally, in the conventional document transport device described above, sheets that have been warped or deformed due to humidity may be supported in a stacked state on the document placement section. In this case, each time a deformed sheet is fed one by one by the pickup roller, the pressing force of the pickup roller on the sheet tends to fluctuate, and the frictional force applied by the friction member to the sheet supported on the document placement section also tends to fluctuate. Consequently, the sheets remaining on the document placement section tend to bounce and move in the feeding direction. As a result, this document transport device may have difficulty suppressing double feeding of sheets.

[0007] The present invention has been made in view of the above-mentioned conventional circumstances, and aims to provide a sheet feeding device that can suppress double feeding of sheets even when deformed sheets are supported on a support surface in a stacked state. [Means for solving the problem]

[0008] The sheet feeding device of the present invention comprises a supply tray having a support surface for supporting sheets in a stacked state, A feeding roller that feeds the sheet supported on the support surface in a feeding direction perpendicular to the width direction of the support surface, A first guide surface located downstream of the support surface in the feeding direction, which guides the sheet fed by the feeding roller, A second guide surface is located downstream of the support surface in the feeding direction and is aligned with the first guide surface in the width direction, and guides a portion of the sheet fed by the feeding roller in the width direction so as to be lifted away from the first guide surface. A friction member having: a first portion provided on the support surface and facing the feed roller from below, which applies a frictional force to the sheet supported on the support surface; and a second portion provided on the first guide surface, aligned with the second guide surface in the width direction, with a portion including the downstream end in the feed direction located below the second guide surface, which is capable of applying a frictional force to the sheet guided by the first guide surface and the second guide surface. It is characterized by having the following features.

[0009] In the sheet feeding device of the present invention, sheets that have been warped or deformed due to moisture may be supported on the support surface of the supply tray in a stacked state. In this case, each time a deformed sheet is fed by the feeding roller, the pressing force of the feeding roller on the sheet tends to fluctuate, and the frictional force applied by the first part of the friction member to the sheet supported on the support surface also tends to fluctuate. For this reason, if no countermeasures are taken, the sheets remaining on the support surface tend to bounce and move in the feeding direction.

[0010] In this regard, the sheet feeding device of the present invention has a first guide surface and a second guide surface. The friction member has not only a first portion but also a second portion.

[0011] Therefore, when the deformed sheets are supported on the support surface in a stacked state, even if the sheets remaining on the support surface bounce and try to be guided by the first and second guide surfaces, the deformed sheets are more likely to come into contact with the second portion of the friction member, and in particular, with a portion of the second portion including the downstream end in the feeding direction. As a result, the second portion can apply a frictional force to the deformed sheets and suppress their movement in the feeding direction.

[0012] Furthermore, when undeformed sheets are supported on the support surface in a stacked state, even if they are fed one by one by the feed roller, the pressing force of the feed roller on the sheets does not fluctuate much, and the frictional force applied by the first part of the friction member to the sheets supported on the support surface also does not fluctuate much. As a result, the sheets remaining on the support surface are less likely to bounce and less likely to move in the feeding direction. When the undeformed sheets are guided by the first and second guide surfaces, they tend to lift from the second part, and in particular, they tend to lift from a part of the second part including the downstream end in the feeding direction, thus suppressing the frictional force applied by the second part to the undeformed sheets. As a result, the problem of undeformed sheets being unnecessarily stopped by the second part can be suppressed.

[0013] Therefore, the sheet feeding device of the present invention can suppress double feeding of sheets even when deformed sheets are supported on the support surface in a stacked state. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] [Figure 1] FIG. 1 is a perspective view of the image reading apparatus of an embodiment. [Figure 2] FIG. 2 is a schematic partial cross-sectional view of the image reading apparatus of the embodiment. [Figure 3] FIG. 3 is a partial perspective view of the image reading apparatus of the embodiment, showing a state where a left end side upper surface cover, a holder, a feeding roller, a separation roller and the like are removed. [Figure 4] FIG. 4 is an enlarged partial perspective view of a main part of FIG. 3. [Figure 5] FIG. 5 is a partial top view showing a support surface, a first guide surface, a second guide surface, a friction member and the like. [Figure 6] FIG. 6 is an enlarged schematic partial cross-sectional view of a main part of FIG. 2. [Figure 7] FIG. 7 is an enlarged schematic partial cross-sectional view of a main part of FIG. 6. [Figure 8] FIG. 8 is a schematic partial cross-sectional view showing the A-A cross-section of FIG. 7, showing a state where undeformed sheets are about to be fed in a multi-fed manner. [Figure 9] FIG. 9 is a schematic partial cross-sectional view showing the same cross-section as FIG. 8, showing a state where deformed sheets are about to be fed in a multi-fed manner. MODES FOR CARRYING OUT THE INVENTION

[0015] Hereinafter, an embodiment embodying the present invention will be described with reference to the drawings.

[0016] (Embodiment) As shown in FIG. 1, the image reading apparatus 1 of the embodiment is an example of a specific embodiment of the sheet feeding apparatus of the present invention. In FIG. 1, the operation panel 8P side of the image reading apparatus 1 is the front side. When facing the operation panel 8P, the side positioned to the left is the left side. The front-rear direction, left-right direction and up-down direction shown in each figure from FIG. 2 onward are all displayed in correspondence with each direction shown in FIG. 1.

[0017] <Overall Configuration> As shown in FIG. 1, an image reading apparatus 1 includes a main body 8 and a cover 9. The main body 8 is a flat, substantially box-shaped body. An operation panel 8P, which is a touch panel or the like, is provided on a front surface of the main body 8. The main body 8 houses an image forming unit 5 in a lower portion thereof. The image forming unit 5 forms an image on a sheet by an inkjet method, a laser method, or the like.

[0018] As shown in FIG. 2, the main body 8 houses an image reading unit 3 in an upper portion thereof. The image reading unit 3 includes a document supporting surface 3A, a reading surface 3B, a reading sensor 3S, and a scanning mechanism (not shown).

[0019] The document supporting surface 3A is an upper surface of a large-area platen glass located on an upper surface of the main body 8. The reading surface 3B is an upper surface of a platen glass that is located on the upper surface of the main body 8 to the left of the document supporting surface 3A and extends elongated in the front-rear direction.

[0020] The document supporting surface 3A supports a document to be read. The document to be read is a sheet such as paper, an OHP sheet, a book, or the like. The reading surface 3B is used when a conveying unit 4 described later operates.

[0021] The reading sensor 3S is a well-known image reading sensor using a CIS (Contact Image Sensor), a CCD (Charge Coupled Device), or the like, and extends elongated in the front-rear direction. The reading sensor 3S is located below the document supporting surface 3A and the reading surface 3B.

[0022] When the image reading unit 3 reads an image of a document supported on the document supporting surface 3A, the reading sensor 3S moves rightward from below the left end edge of the document supporting surface 3A, i.e., in the sub-scanning direction, by the operation of a scanning mechanism (not shown), and reads the image of the document in a line shape in the front-rear direction, i.e., the main scanning direction. When the reading sensor 3S moves to a position below the right end edge of the document supporting surface 3A, it completes the image reading and returns to a standby position by the operation of the scanning mechanism (not shown).

[0023] When the transport unit 4, which will be described later, is in operation, the reading sensor 3S moves to a stationary reading position below the reading surface 3B and remains stationary due to the operation of a scanning mechanism (not shown).

[0024] As shown in Figure 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 pivotable around a pivot axis X9 that extends in the left-right direction.

[0025] As shown in Figure 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 is large enough to cover the document support surface 3A and the reading surface 3B. The bottom surface of the cover 9 can cover the document placed on the document support surface 3A.

[0026] The base member 39 is a one-piece molded product made of resin material. In this embodiment, the base member 39 is manufactured by injection molding of thermoplastic resin or the like.

[0027] Although not shown in the diagram, the user swings the cover 9 upward and backward around the pivot axis X9, thereby opening the document support surface 3A. In this state, the user can place a document on the document support surface 3A and remove the document.

[0028] As shown in Figures 1 and 2, the cover 9 has a supply tray 90 and a discharge tray 96. The supply tray 90 and the discharge tray 96 are located on the right side of the cover 9.

[0029] As shown in Figure 2, the upper surface of the right portion of the base member 39 forms an output tray 96. The output tray 96 supports the sheet SH from which the image is read and output.

[0030] The supply tray 90 is located above the discharge tray 96. The supply tray 90 has a support surface 95. The support surface 95 supports the sheets SH in a stacked state before the images are read.

[0031] In this embodiment, the object from which the image is read using the document support surface 3A is referred to as the document, and the object supported by the support surface 95 and transported by the transport unit 4 while the image is read is referred to as the sheet SH. The document and the sheet SH may be substantially the same thing.

[0032] The support surface 95 extends with a gentle downward slope to the left and also extends in the front-rear direction. The width direction of the support surface 95 is the front-rear direction. In this embodiment, one end in the width direction is the front, and the other end in the width direction is the rear.

[0033] The feeding direction DF1 for feeding the sheet SH supported on the support surface 95 is a leftward direction and is perpendicular to the width direction.

[0034] The downstream end 95D of the feeding direction DF1 on the support surface 95 is located between the left side of the cover 9 and the central part in the left-right direction.

[0035] As shown in Figures 2 and 3, the cover 9 has an upper chute 34. The upper chute 34 is located above the left portion of the base member 39 and below the left end upper surface cover 98, and extends in the left-right and width directions. Although not shown in the figures, the front and rear ends of the upper chute 34 are assembled to the front and rear ends of the left portion of the base member 39.

[0036] The upper chute 34 integrally comprises a first tray 91, which is the right portion of the upper chute 34, and a guide portion 34A, which is the left portion of the upper chute 34. The first tray 91 extends from the right end of the upper chute 34 so as to slope gently downward to the left. The guide portion 34A extends so as to slope gently upward to the left, and then curves downward. The upper surface of the guide portion 34A constitutes the transport guide surface 34G.

[0037] The upper chute 34 is a single molded product made of resin material. In this embodiment, the upper chute 34 is manufactured by injection molding of thermoplastic resin or the like.

[0038] <Specific configuration of the supply tray> The supply tray 90 includes the first tray 91 described above, and the second tray 92 and sub-tray 93 shown in Figures 1 to 3.

[0039] The first tray 91 has a first support surface 91S formed by its upper surface. The first support surface 91S is part of the support surface 95 and includes the downstream end 95D of the support surface 95.

[0040] The first portion 71 of the friction member 70, which will be described later, is attached to the central part in the width direction of the first support surface 91S.

[0041] As shown in Figures 2 and 3, the second tray 92 is located to the right of the first tray 91. The second tray 92 extends with a gentle downward slope to the left and also extends in the width direction. Although not shown in the figures, the front and rear ends of the second tray 92 are assembled to the front and rear ends of the left portion of the base member 39 to the right of the first tray 91. The upper surface of the second tray 92 constitutes the second support surface 92S. The second support surface 92S is adjacent to the first support surface 91S from the upstream side in the feeding direction DF1.

[0042] The sub-tray 93 is located to the right of the second tray 92 and is connected to the front and rear ends (not shown) of the second tray 92. The upper surface of the sub-tray 93 constitutes a third support surface 93S. The third support surface 93S is adjacent to the second support surface 92S from the upstream side in the feeding direction DF1.

[0043] The second support surface 92S and the third support surface 93S are the remaining portion of the support surface 95 excluding the first support surface 91S.

[0044] As shown in Figures 1 and 3, the supply tray 90 has side guides 92A and 92B. The side guides 92A and 92B are positioned on the second support surface 92S of the second tray 92 and are slidable in the front-rear direction. By sliding closer to and further apart from each other, the side guides 92A and 92B position sheets SH of various sizes supported on the support surface 95 in the front-rear direction (width direction). In this embodiment, the sheets SH to be image read include A5 to A4 size paper, postcards, etc.

[0045] <First guide surface, rib, and second guide surface> As shown in Figures 3 to 5, the upper chute 34 has a first guide surface 61, two ribs 69, and two second guide surfaces 62. The first guide surface 61, each rib 69, and each second guide surface 62 are located downstream of the support surface 95 in the feeding direction DF1. The first guide surface 61 and each second guide surface 62 constitute a part of the conveying guide surface 34G.

[0046] As shown in Figure 3, the upstream end of the first guide surface 61 in the feeding direction DF1 is connected to the downstream end 95D of the support surface 95. The widthwise length of the first guide surface 61 is the same as the widthwise length of the support surface 95. The first guide surface 61 is inclined to rise as it progresses in the feeding direction DF1.

[0047] As shown in Figure 4, the upper chute 34 has a substantially rectangular opening 34H. The opening 34H is located in the center of the width direction of the first guide surface 61. A separation holder 42B, which will be described later, is placed inside the opening 34H.

[0048] Each rib 69 protrudes upward from the first guide surface 61 in the width direction, with the opening 34H and the separation holder 42B positioned between them, and extends in the feeding direction DF1. Each rib 69 has a roughly triangular shape when viewed along the width direction, with the length of its base being significantly greater than the length from the base to the apex.

[0049] Each second guide surface 62 is the upper end surface of each rib 69. Each second guide surface 62 is aligned with the first guide surface 61 in the width direction. Each second guide surface 62 is provided such that the opening 34H and the separation holder 42B are positioned between them in the width direction. Each second guide surface 62 has a first inclined surface 62A and a second inclined surface 62B.

[0050] The upstream end of the feed direction DF1 on the first inclined surface 62A is connected to the downstream end 95D of the support surface 95. The first inclined surface 62A is inclined to rise as it progresses in the feed direction DF1. In other words, the first inclined surface 62A is inclined such that the distance upward from the first guide surface 61 increases as it progresses in the feed direction DF1.

[0051] The second inclined surface 62B is connected to the first inclined surface 62A at the connection part 62C. The second inclined surface 62B is inclined to descend as it moves in the feeding direction DF1. In other words, the second inclined surface 62B is inclined such that the distance it moves upward from the first guide surface 61 decreases as it moves in the feeding direction DF1.

[0052] <Conveying section and 1st to 3rd conveying guides> As shown in Figure 2, the cover 9 has a transport section 4, a first transport guide 31, a second transport guide 32, and a third transport guide 33. The transport section 4, the first transport guide 31, the second transport guide 32, and the third transport guide 33 are located inside the left portion of the cover 9.

[0053] The conveying section 4 includes a feeding roller 41, a separation roller 42, a separation holder 42B, a separation pad 42A, a holder 50, a first conveying roller pair 43, a pressing member 44, a second conveying roller pair 45, a discharge roller 47, and an elastic piece 48.

[0054] The feed roller 41 is located upstream of the downstream end 95D of the support surface 95 in the feed direction DF1. The feed roller 41 is positioned above the center of the width direction of the first support surface 91S.

[0055] The separation roller 42 is located downstream in the feeding direction DF1 from the feed roller 41 and the downstream end 95D of the support surface 95. The separation roller 42 faces the conveying guide surface 34G from above. The separation roller 42 is mounted on a drive shaft 42S centered on a drive axis X42 that extends in the width direction.

[0056] As shown in Figure 6, the connection portion 62C between the first inclined surface 62A and the second inclined surface 62B on each second guide surface 62 is located upstream of the separation roller 42 in the feeding direction DF1.

[0057] As shown in Figure 2, the separation holder 42B is located within the opening 34H of the transport guide surface 34G and faces the separation roller 42 from below. The separation holder 42B is pivotably supported by the guide portion 34A and can move closer to and further away from the separation roller 42.

[0058] The separation pad 42A is located on the separation holder 42B. The biasing spring biases the separation holder 42B upward, causing the separation pad 42A to be pressed toward the separation roller 42.

[0059] As shown in Figure 2, the holder 50 has the drive shaft 42S inserted through it. The holder 50 extends to the right of the drive shaft center X42 and rotatably supports the feed roller 41 at its right end.

[0060] A torque limiter (not shown) is interposed between the holder 50 and the drive shaft 42S. The holder 50 supports a gear train (not shown) that transmits driving force from the drive shaft 42S to the feed roller 41.

[0061] The drive shaft 42S rotates around the drive shaft center X42 when the driving force from a drive source (not shown) is transmitted to it.

[0062] When the drive source (not shown) rotates in the forward direction, the torque limiter (not shown) causes the holder 50 to rotate in accordance with the rotation of the drive shaft 42S. This causes the holder 50 to swing so as to lower the feed roller 41. When the feed roller 41 contacts the uppermost sheet SH supported on the support surface 95, the torque limiter (not shown) slips internally to hold the holder 50 in that position. As a result, the feed roller 41 presses the sheet SH supported on the support surface 95 downward.

[0063] In this case, the drive shaft 42S transmits driving force to the separation roller 42, causing the separation roller 42 to rotate around the drive shaft center X42, and also transmits driving force to the feed roller 41 via a gear train (not shown), causing the feed roller 41 to rotate. The feed roller 41 feeds the uppermost sheet SH, supported on the support surface 95, in the feed direction DF1. The first guide surface 61 of the transport guide surface 34G guides the sheet SH being fed by the feed roller 41. Each second guide surface 62 of the transport guide surface 34G guides the sheet SH being fed by the feed roller 41 so that its widthwise central portion is lifted away from the first guide surface 61. The separation roller 42 transports the sheet SH, fed by the feed roller 41 and guided by the first guide surface 61 and each second guide surface 62, in the feed direction DF1. In this process, the separation roller 42 and separation pad 42A separate the sheets SH being fed by the feed roller 41 into individual sheets if there are multiple sheets SH, and then transport the sheets SH.

[0064] If the drive source (not shown) rotates in the reverse direction, the torque limiter (not shown) causes the holder 50 to rotate in the opposite direction to the drive shaft 42S. As a result, the holder 50 swings to raise the feed roller 41.

[0065] The position of the feed roller 41 (41U) shown in Figures 2, 6, and 7 is the upper limit position. When the feed roller 41 reaches the upper limit position, a torque limiter (not shown) slips internally to hold the holder 50 in that position.

[0066] In this case, the rotation of the separation roller 42 and the feed roller 41 is meaningless, so the control unit (not shown) immediately stops the drive source (not shown) when the feed roller 41 reaches the upper limit position. The torque limiter (not shown) holds the holder 50 in that position even after the drive source (not shown) has stopped.

[0067] The feed roller 41 can contact the first portion 71 of the friction member 70, which will be described later, when there is no sheet SH supported on the support surface 95. The position of the feed roller 41 (41D) shown in Figures 2, 6, and 7 is the lower limit position at which the feed roller 41 contacts the first portion 71 of the friction member 70, which will be described later.

[0068] As shown in Figure 2, the first transport roller pair 43 is located on the left side wall of the cover 9, close to the top surface of the main body 8. The pressing member 44 is located directly above the reading surface 3B.

[0069] The first transport guide 31 consists of a transport guide surface 34G and ribs that protrude downward from the back surface of the left end upper cover 98. The first transport guide 31 guides the sheet SH, which is supported on the support surface 95, to the first transport roller pair 43.

[0070] The second transport guide 32 consists of a part of the chute member located below the guide portion 34A of the upper chute 34 inside the cover 9, or a guide surface formed inside the left side of the cover 9.

[0071] The second transport guide 32 guides the sheet SH so that it slopes downward from the first transport roller pair 43 to the reading surface 3B, and then guides it so that it passes between the pressing member 44 and the reading surface 3B, that is, above the reading sensor 3S which is in the stationary reading position.

[0072] The second conveyor roller pair 45 is located above and to the left of the left edge of the discharge tray 96. The discharge roller 47 is located above the left edge of the discharge tray 96 and slightly to the left of the left edge of the discharge tray 96. The upper end of the discharge roller 47 is located above the nip position of the second conveyor roller pair 45.

[0073] The elastic piece 48 is made of a highly rigid film. The elastic piece 48 is cantilevered between the second conveyor roller pair 45 and the discharge roller 47, protruding to the right, and bends to the right of the discharge roller 47, sloping downward to the right.

[0074] Although not shown in the diagram, the conveying section 4 has a plurality of discharge rollers 47 and a plurality of elastic pieces 48, and the discharge rollers 47 and elastic pieces 48 are arranged alternately in the width direction.

[0075] The third transport guide 33 consists of the lower surface of the chute member located below the first tray 91 and the second tray 92 inside the cover 9, and an upward transport guide surface formed between the reading surface 3B of the base member 39 and the discharge tray 96.

[0076] The third transport guide 33 guides the sheet SH to the right of the reading surface 3B so that it slopes upward to the right, passing through the second transport roller pair 45, and further guides the sheet SH to the discharge roller 47 and elastic piece 48.

[0077] <Friction component> As shown in Figures 4 to 7, the image reading device 1 is equipped with a friction member 70. The friction member 70 has a first portion 71 and two second portions 72. The first portion 71 and each of the second portions 72 are continuous in the feeding direction DF1.

[0078] The friction member 70 is made of a material capable of applying a higher frictional force to the sheet SH than the resin material constituting the first tray 91, such as cork, rubber, or elastomer. In this embodiment, the friction member 70 is made by integrally cutting out the first portion 71 and each of the second portions 72 from a cork sheet with a thickness of about 1 mm.

[0079] As shown in Figure 4, the first portion 71 is provided on the support surface 95. More specifically, the first portion 71 is attached to the center of the first support surface 91S in the width direction using double-sided tape or the like.

[0080] As shown in Figure 5, the first part 71 is rectangular in shape, with a length in the width direction greater than the length of the feed direction DF1. In this embodiment, the length of the first part 71 in the width direction is approximately 61 mm as an example. In this embodiment, the length of the feed roller 41 in the width direction is approximately 27 mm as an example. In this embodiment, the length of the first part 71 in the width direction is approximately 2 to 3 times the length of the feed roller 41 in the width direction as an example.

[0081] As shown in Figures 5 and 7, the upstream end 71U of the feed direction DF1 in the first section 71 is located near the upstream end of the feed direction DF1 in the first support surface 91S. The downstream end 71D of the feed direction DF1 in the first section 71 is located slightly upstream of the feed direction DF1 from the downstream end 95D of the support surface 95.

[0082] As shown in Figure 6, the first portion 71 faces the feed roller 41 from below. The first portion 71 contacts the bottom sheet SH supported by the support surface 95 and applies a frictional force. As shown in Figure 7, the first portion 71 contacts the feed roller 41 (41D) when it has descended to its lower limit position when there is no sheet SH supported by the support surface 95.

[0083] As shown in Figure 5, each second portion 72 is rectangular in shape and significantly smaller than the first portion 71. A second portion 72 located on one side in the width direction connects to a portion of the first portion 71 located on the same side in the width direction at the downstream end 71D of the first portion 71. A second portion 72 located on the other side in the width direction connects to a portion of the first portion 71 located on the other side in the width direction at the downstream end 71D of the first portion 71. The first portion 71 and each second portion 72 are roughly U-shaped when viewed along the vertical direction.

[0084] Each second portion 72 is provided on the first guide surface 61. More specifically, the second portion 72 located on one side in the width direction is located on the opposite side of the opening 34H and the separation holder 42B from the second guide surface 62 located on one side in the width direction, and is attached to the first guide surface 61 by double-sided tape or the like. The second portion 72 located on the other side in the width direction is located on the opposite side of the opening 34H and the separation holder 42B from the second guide surface 62 located on the other side in the width direction, and is attached to the first guide surface 61 by double-sided tape or the like.

[0085] In other words, each second portion 72 is aligned with each second guide surface 62 in the width direction. Each second portion 72 is provided such that each second guide surface 62 is positioned between them in the width direction. Each second portion 72 is provided such that the opening 34H and the separation holder 42B are positioned between them in the width direction.

[0086] As shown in Figure 4, each second portion 72 is inclined to rise as it moves along the first guide surface 61 in the feeding direction DF1.

[0087] As shown in Figures 4 and 7, each second portion 72 has a portion, including the downstream end 72D in the feeding direction DF1, located below the second guide surface 62.

[0088] As shown in Figures 8 and 9, each second portion 72 can apply a frictional force to the sheet SH guided by the first guide surface 61 and each second guide surface 62.

[0089] More specifically, as shown in Figure 8, when the undeformed sheet SH is guided by the first guide surface 61 and each second guide surface 62, the portion facing each second portion 72 is less likely to sag. As a result, the undeformed sheet SH is more likely to lift away from each second portion 72, and in particular, it is more likely to lift away from a portion of each second portion 72 including the downstream end 72D in the feeding direction DF1. Consequently, the frictional force exerted by each second portion 72 on the undeformed sheet SH is suppressed.

[0090] As shown in Figure 9, when a deformed sheet SH, particularly a sheet SH that is deformed to be wavy along the width direction, is guided by the first guide surface 61 and each second guide surface 62, the portion facing each second portion 72 tends to sag. As a result, the deformed sheet SH is more likely to come into contact with each second portion 72, and in particular, it is more likely to come into contact with a portion of each second portion 72 including the downstream end 72D in the feeding direction DF1. Consequently, each second portion 72 is more likely to exert frictional force on its sheet SH.

[0091] <Image reading operation of a sheet supported on a support surface> In the image reading device 1, when the image reading unit 3 reads an image of a sheet SH supported on a support surface 95, a control unit (not shown) rotates a drive source (not shown) in the forward direction to operate the transport unit 4.

[0092] The conveying unit 4 rotates the feeding roller 41 and the separating roller 42 in the clockwise direction in Figure 2, rotates the drive roller 43A of the first conveying roller pair 43 and the drive roller 45A of the second conveying roller pair 45 in the counterclockwise direction in Figure 2, and rotates the discharge roller 47 in the clockwise direction in Figure 2.

[0093] As a result, the holder 50 swings to lower the feed roller 41 (41U) which is in the upper limit position, and the feed roller 41 comes into contact with the uppermost sheet SH supported by the support surface 95. At this time, the feed roller 41 presses downward against the uppermost sheet SH supported by the support surface 95.

[0094] The feed roller 41 then feeds the uppermost sheet SH, supported by the support surface 95, in the feeding direction DF1. At this time, the first portion 71 of the friction member 70 contacts the lowest sheet SH, supported by the support surface 95, and applies a frictional force. When the sheet SH guided by the first guide surface 61 and the second guide surfaces 62 is deformed in a wavy manner along the width direction, each second portion 72 of the friction member 70 is more likely to contact the portion of the sheet SH opposite each second portion 72, and thus more likely to apply a frictional force to the sheet SH. As a result, the image reading device 1 can suppress double feeding of the sheet SH.

[0095] The separation roller 42 and separation pad 42A separate the sheets SH being fed by the feed roller 41 into individual sheets if there are multiple sheets, and then transport the sheets SH toward the first transport roller pair 43.

[0096] Next, the first transport roller pair 43 transports the sheet SH, guided by the first transport guide 31 and the second transport guide 32, so that it passes over the reading sensor 3S, which is in a stationary reading position. As a result, the reading sensor 3S reads the image of the sheet SH.

[0097] Subsequently, the second transport roller pair 45 transports the sheet SH, which is guided by the third transport guide 33, toward the discharge roller 47 and elastic piece 48. The discharge roller 47 and elastic piece 48 discharge the sheet SH into the discharge tray 96 while deforming it into a corrugated shape.

[0098] In this process, 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 conveyor roller pair 45.

[0099] When the image reading operation of sheet SH is completed, a control unit (not shown) briefly reverses the rotation of a drive source (not shown). This causes the holder 50 to swing so that the feed roller 41 rises to the upper limit position. As a result, the feed roller 41 (41U), which has moved to the upper limit position, returns to a state where it is separated above the uppermost sheet SH supported by the support surface 95.

[0100] <Effects and Effects> In the image reading device 1 of the embodiment, deformed sheets SH that have been warped or warped due to moisture may be supported on the support surface 95 of the supply tray 90 in a stacked state. In this case, each time a deformed sheet SH is fed one by one by the feed roller 41, the pressing force of the feed roller 41 on the sheet SH tends to fluctuate, and the frictional force that the first portion 71 of the friction member 70 acts on the sheet SH supported on the support surface 95 also tends to fluctuate. For this reason, if no countermeasures are taken, the sheet SH remaining on the support surface 95 tends to bounce and move in the feeding direction DF1.

[0101] In this regard, the image reading device 1 of the embodiment has a first guide surface 61 and two second guide surfaces 62, as shown in Figures 4 and 5. The friction member 70 has not only the first portion 71 but also two second portions 72.

[0102] Therefore, as shown in Figure 9, when a deformed sheet SH, particularly a sheet SH deformed to undulate along the width direction, is supported on the support surface 95 in a stacked state, even if the sheet SH remaining on the support surface 95 bounces and tries to be guided to the first guide surface 61 and each second guide surface 62, the deformed sheet SH is more likely to come into contact with each second portion 72, and in particular, a portion of each second portion 72 including the downstream end 72D in the feeding direction DF1. As a result, each second portion 72 can apply frictional force to the deformed sheet SH and suppress its advance in the feeding direction DF1.

[0103] As shown in Figure 8, when undeformed sheets SH are supported on the support surface 95 in a stacked state, even when they are fed one by one by the feed roller 41, the pressing force of the feed roller 41 on the sheets SH does not fluctuate much, and the frictional force that the first portion 71 of the friction member 70 applies to the sheets SH supported on the support surface 95 also does not fluctuate much. Therefore, the sheets SH remaining on the support surface 95 are less likely to bounce and less likely to advance in the feeding direction DF1. Furthermore, when the undeformed sheets SH are guided by the first guide surface 61 and each second guide surface 62, they tend to lift off each second portion 72, and in particular, they tend to lift off from a part of each second portion 72 including the downstream end 72D in the feeding direction DF1, thus suppressing the application of frictional force by each second portion 72 to the undeformed sheets SH. As a result, the problem of undeformed sheets SH being unnecessarily stopped by each second portion 72 can be suppressed.

[0104] Therefore, the image reading device 1 of the embodiment can suppress double feeding of sheets SH even when deformed sheets SH are supported on the support surface 95 in a stacked state.

[0105] Furthermore, in this image reading device 1, as shown in Figure 4, each second guide surface 62 is provided such that the opening 34H and the separation holder 42B are positioned between each other in the width direction. Each second portion 72 is provided such that the opening 34H and the separation holder 42B are positioned between each other in the width direction. With this configuration, as shown in Figure 9, when the deformed sheet SH is guided to the first guide surface 61 and each second guide surface 62, each second portion 72 is positioned below the portion of the sheet SH that is prone to sagging. As a result, even if the sheet SH remaining on the support surface 95 bounces and tries to be guided to the first guide surface 61 and each second guide surface 62, the image reading device 1 can reliably apply frictional force to the deformed sheet SH with high reliability, thereby reliably suppressing its movement in the feeding direction DF1. In addition, this configuration can suppress the slanting of the sheet SH guided to the first guide surface 61 and each second guide surface 62.

[0106] Furthermore, in this image reading device 1, as shown in Figure 4, each second portion 72 is provided such that each second guide surface 62 is positioned between them in the width direction. With this configuration, as shown in Figure 9, when the deformed sheet SH is guided to the first guide surface 61 and each second guide surface 62, each second portion 72 is reliably positioned below the portion of the sheet SH that is prone to sagging. As a result, even if the sheet SH remaining on the support surface 95 bounces and tries to be guided to the first guide surface 61 and each second guide surface 62, the image reading device 1 can more reliably apply frictional force to the deformed sheet SH with greater reliability, thereby more reliably suppressing its movement in the feeding direction DF1.

[0107] Furthermore, in this image reading device 1, as shown in Figure 4, the first portion 71 and each of the second portions 72 are continuous in the feeding direction DF1. This configuration makes it less likely for the leading edge of the sheet SH fed by the feeding roller 41 to get caught between the first portion 71 and each of the second portions 72.

[0108] Furthermore, in this image reading device 1, each second guide surface 62 is the upper end surface of each rib 69 that protrudes upward from the first guide surface 61 and extends in the feeding direction DF1. With this configuration, each second guide surface 62 can reliably lift the central part in the width direction of the sheet SH fed by the feeding roller 41 away from the first guide surface 61.

[0109] Furthermore, in this image reading device 1, each second guide surface 62 has a first inclined surface 62A and a second inclined surface 62B. As shown in Figure 6, the connection portion 62C between the first inclined surface 62A and the second inclined surface 62B is located upstream of the separation roller 42 in the feeding direction DF1. With this configuration, each second guide surface 62 can reliably lift the central part in the width direction of the sheet SH fed by the feeding roller 41 from the first guide surface 61 by the first inclined surface 62A, and then smoothly guide the sheet SH to the nip position between the separation roller 42 and the separation pad 42A by the second inclined surface 62B.

[0110] Furthermore, in this image reading device 1, as shown in Figure 4, the first guide surface 61 is inclined to rise as it moves in the feeding direction DF1. With this configuration, when the leading edge of the sheet SH fed by the feeding roller 41 rises along the first guide surface 61, if the sheet SH is deformed, it is more likely to come into contact with each of the second portions 72 provided on the first guide surface 61. Therefore, when deformed sheets SH are supported on the support surface 95 in a stacked state, even if the sheets SH remaining on the support surface 95 bounce and try to be guided to the first guide surface 61 and each of the second guide surfaces 62, each of the second portions 72 can reliably apply frictional force to the deformed sheets SH, reliably preventing them from moving in the feeding direction DF1.

[0111] Although the present invention has been described above with reference to examples, it goes without saying that the present invention is not limited to the above examples and can be applied with appropriate modifications without departing from its spirit.

[0112] In the embodiments, the sheet feeding device of the present invention was embodied as an image reading device 1 equipped with an image forming function and an image reading function, but the present invention is not limited to this configuration. For example, the configuration of the present invention may be applied to an image reading device equipped only with an image reading function, or to an image forming device equipped only with an image forming function.

[0113] In the embodiment, the first portion 71 and the second portion 72 are continuous in the feeding direction DF1, but the present invention is not limited to this configuration. For example, the present invention also includes a configuration in which the first portion 71 and the second portion 72 are separate, and the upstream end of the second portion 72 in the feeding direction DF1 is located below the downstream end 71D of the first portion 71, creating a step difference.

[0114] In the embodiment, each second portion 72 is provided such that each second guide surface 62 is positioned between them in the width direction, but the present invention is not limited to this configuration. For example, a configuration in which each second guide surface is provided such that each second portion is positioned between them in the width direction is also included in the present invention. [Explanation of Symbols]

[0115] 1...Sheet feeding device (image reading device), SH...Sheet 95...Support surface, 90...Supply tray DF1...feeding direction, 41...feeding roller 61...First guide surface, 62...Second guide surface 71...first part, 72...second part 72D... Downstream end in the feeding direction of the second part, 70... Friction member 42...Separation roller, 42B...Separation holder 42A...Separation pad, 69...Rib 62A...first inclined surface, 62B...second inclined surface 62C...Connection between the first and second inclined surfaces

Claims

1. A supply tray having a support surface for supporting sheets in a stacked state, A feeding roller that feeds the sheet supported on the support surface in a feeding direction perpendicular to the width direction of the support surface, A first guide surface located downstream of the support surface in the feeding direction, which guides the sheet fed by the feeding roller, A second guide surface is located downstream of the support surface in the feeding direction and is aligned with the first guide surface in the width direction, and guides a portion of the sheet fed by the feeding roller in the width direction so as to be lifted away from the first guide surface. A friction member having: a first portion provided on the support surface and facing the feed roller from below, which applies a frictional force to the sheet supported on the support surface; and a second portion provided on the first guide surface, aligned with the second guide surface in the width direction, with a portion including the downstream end in the feed direction located below the second guide surface, which is capable of applying a frictional force to the sheet guided by the first guide surface and the second guide surface. A sheet feeding device characterized by being equipped with the following features.

2. A separation roller located downstream of the feeding roller in the feeding direction, which conveys the sheet guided by the first guide surface and the second guide surface in the feeding direction, A separation holder is positioned below the separation roller and is capable of approaching and moving away from the separation roller, A separation pad located on the separation holder and pressed toward the separation roller, Equipped with, The two second guide surfaces are provided such that they position the separation holder between each other in the width direction, The sheet feeding device according to claim 1, wherein the two second portions are arranged such that the separation holder is positioned between them in the width direction.

3. The sheet feeding device according to claim 2, wherein each of the second portions is provided such that each of the second guide surfaces is positioned between each other in the width direction.

4. The sheet feeding device according to any one of claims 1 to 3, wherein the first portion and the second portion are continuous in the feeding direction.

5. The sheet feeding device according to claim 2 or 3, wherein each of the second guide surfaces is the upper end surface of a rib that protrudes upward from the first guide surface and extends in the feeding direction.

6. Each of the second guide surfaces has a first inclined surface that slopes upward as it moves in the feeding direction, and a second inclined surface connected to the first inclined surface that slopes downward as it moves in the feeding direction. The sheet feeding device according to claim 5, wherein the connection between the first inclined surface and the second inclined surface is located upstream of the separation roller in the feeding direction.

7. The sheet feeding device according to any one of claims 1 to 3, wherein the first guide surface is inclined to rise as it moves in the feeding direction.

Images