Sheet feeding device

Abstract

The present invention provides a sheet feeding device that can reliably align the tip of a sheet, even when the sheet has an upward-curling tip and is inserted along a support surface. [Solution] In the sheet feeding device 1, the shutter 70 has a plurality of first restricting surfaces 71 and at least one second restricting surface 72 that can contact the leading edge of the sheet SH being inserted when the shutter 70 is in the restricting position. Each first restricting surface 71 is arranged vertically and faces upstream in the feeding direction DF1. The second restricting surface 72 is a surface that is located between each first restricting surface 71 and faces downward. If two adjacent first restricting surfaces 71 in the vertical direction are designated as the first surface and the other as the second surface, the entire second surface is located downstream in the feeding direction DF1 from the first surface, and the second restricting surface 72 located between the first surface and the second surface is connected to the lower end of the first surface and the upper end of the second surface.

Description

[[Technical Field]]

[0001] The present invention relates to a sheet feeding apparatus. [[Background Art]]

[0002] Patent Document 1 discloses an automatic paper feeder, which is an example of a conventional sheet feeding apparatus. In this automatic paper feeder, a document supply tray has a supporting surface that supports a document. A pickup roller feeds the document supported on the supporting surface in a feeding direction. A stopper swings between a paper stopping position where it restricts the leading edge of an inserted document and a paper passing position where it retracts from the document fed by the pickup roller.

[0003] The stopper has a restricting surface. When the stopper is located at the paper stopping position, the restricting surface is a flat surface that faces upstream in the feeding direction and extends in the vertical direction, and is capable of coming into contact with the leading edge of the inserted document. By means of such a restricting surface, the stopper aligns the leading edges of inserted documents when the stopper is at the paper stopping position. [[Prior Art Documents]] [[Patent Documents]]

[0004] [[Patent Document 1]] Japanese Patent Laid-Open No. 2007-230782 [[Summary of the Invention]] [[Problem to be Solved by the Invention]]

[0005] However, in the above-described conventional automatic paper feeder, when a document with an upward-curled leading edge is inserted, the leading edge of the document is prone to lift up when it comes into contact with the restricting surface of the stopper. As a result, this automatic paper feeder may have difficulty aligning the upward-curled leading edges of sheets.

[0006] The present invention has been made in view of the above-mentioned conventional circumstances, and aims to provide a sheet feeding device that can reliably align the tip of a sheet even when a sheet with an upward-curling tip is inserted along a support surface. [Means for solving the problem]

[0007] The sheet feeding device of the present invention comprises a supply tray having a support surface for supporting sheets, 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 shutter that swings between a restricting position that restricts the leading edge of the sheet inserted along the support surface and a retracted position that moves away from the sheet being fed by the feed roller, A sheet feeding device equipped with, The shutter has a plurality of first restricting surfaces and at least one second restricting surface that can contact the leading edge of the sheet inserted along the support surface when the shutter is in the restricting position, Each of the first regulating surfaces is aligned in the vertical direction and faces upstream in the feeding direction. The second restricting surface is a surface located between each of the first restricting surfaces and facing downwards. If, of the two adjacent first restricting surfaces in the vertical direction, the one located above is designated as the first surface and the other as the second surface, The entirety of the second surface is located downstream of the first surface in the feeding direction, and the second regulating surface, located between the first surface and the second surface, is characterized by being connected to the lower end of the first surface and the upper end of the second surface.

[0008] In the sheet feeding device of the present invention, if two first restricting surfaces adjacent to each other in the vertical direction are designated as the first surface (the one located above the other) and the second surface (the other), the entirety of the second surface is located downstream of the first surface in the feeding direction, and the second restricting surface located between the first and second surfaces is connected to the lower end of the first surface and the upper end of the second surface. This relationship means that each first and second restricting surface forms a stepped slope, and that this stepped slope extends so as it approaches the support surface, it shifts downstream in the feeding direction.

[0009] With this configuration, each first restricting surface can reliably restrict the sheet by guiding the tip of the sheet downwards so that it approaches the support surface, regardless of whether the tip of the sheet inserted along the support surface is curled upwards or not.

[0010] Furthermore, the second regulating surface can hold down the tip of a sheet that curls upward when it is inserted along the support surface, thereby preventing the tip of the sheet from rising.

[0011] Therefore, the sheet feeding device of the present invention can reliably align the tips of sheets even when sheets with upward-curling tips are inserted along a support surface. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 is a perspective view of the image reading device in the embodiment. [Figure 2] Figure 2 is a schematic partial cross-sectional view of the image reading device of the embodiment. [Figure 3] Figure 3 is a partial perspective view showing the cover, with the left-end top cover in the closed position not shown, and the holder, shutter, etc. assembled to the left-end top cover. [Figure 4] Figure 4 is a partial perspective view showing the cover, with the top left cover, holder, shutter, etc., removed. [Figure 5]Fig. 5 is a schematic partial sectional view showing a shutter whose swinging from a restricting position to a retracted position is restricted by a lock member located at a locked position. [Figure 6] Fig. 6 is a schematic partial sectional view showing a shutter whose swinging from a restricting position to a retracted position is allowed by a lock member located at an unlocked position. [Figure 7] Fig. 7 is a side view of the shutter. [Figure 8] Fig. 8 is a perspective view of the shutter. [Figure 9] Fig. 9 is a schematic partial sectional view showing a state where an abutment surface of an actuator does not abut against a leading end of a sheet inserted along a support surface. [Figure 10] Fig. 10 is a schematic partial sectional view showing a state after an abutment surface of an actuator abuts against a leading end of a sheet inserted along a support surface. MODE FOR CARRYING OUT THE INVENTION

[0013] Hereinafter, embodiments embodying the present invention will be described with reference to the drawings.

[0014] Example As shown in Fig. 1, an image reading apparatus 1 according to 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. The side that is on the left when facing the operation panel 8P 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 corresponding to each direction shown in Fig. 1.

[0015] <Overall Structure> As shown in Fig. 1, the 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 located on the front surface of the main body 8. The main body 8 accommodates an image forming section 5 in its lower portion. The image forming section 5 forms an image on a sheet by an inkjet method, a laser method, or the like.

[0016] As shown in Figure 2, the main body 8 houses the image reading unit 3 in its upper portion. The image reading unit 3 has a document support surface 3A, a reading surface 3B, a first reading sensor 3S, and a scanning mechanism (not shown).

[0017] The document support surface 3A is the upper surface of a large platen glass located on the top surface of the main body 8. The reading surface 3B is the upper surface of a platen glass located to the left of the document support surface 3A on the top surface of the main body 8 and extending in a long, narrow shape in the front-to-back direction. A scoop guide 7 is located between the document support surface 3A and the reading surface 3B on the top surface of the main body 8. The scoop guide 7 protrudes upward and extends in a long, narrow shape in the front-to-back direction.

[0018] The document support surface 3A supports the document to be scanned. Documents to be scanned include paper, OHP sheets, books, etc. The scanning surface 3B and the scoop guide 7 are used when the transport unit 4, described later, is in operation.

[0019] The first reading sensor 3S is a well-known image reading sensor that uses a CIS (Contact Image Sensor) or CCD (Charge Coupled Device), and is elongated in the front-to-back direction. The first reading sensor 3S is located below the document support surface 3A and the reading surface 3B.

[0020] When the image reading unit 3 reads an image of a document supported on the document support surface 3A, the first reading sensor 3S moves from below the left edge of the document support surface 3A toward the right, i.e., in the sub-scanning direction, and reads the image of the document in a line in the front-to-back direction, i.e., in the main scanning direction, through the operation of a scanning mechanism (not shown). When the first reading sensor 3S moves to below the right edge of the document support surface 3A, it finishes reading the image and returns to the standby position through the operation of a scanning mechanism (not shown).

[0021] When the transport unit 4, which will be described later, is in operation, the first 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).

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] The cover 9 has a lower chute 37, an upper chute 34, and a left-end upper cover 20. The lower chute 37 is located above the left portion of the base member 39. The upper chute 34 is located above the lower chute 37 and below the left-end upper cover 20.

[0034] In this embodiment, the lower chute 37, the upper chute 34, and the left end upper cover 20 are each integrally molded products made of resin material, and are manufactured by injection molding of thermoplastic resin or the like.

[0035] As shown in Figures 3 and 4, the upper chute 34 extends in the left-right direction and the width direction. Although not shown in the figures, the lower chute 37 also extends in the left-right direction and the width direction. Although not shown in the figures, the front and rear ends of the upper chute 34 and the front and rear ends of the lower chute 37 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 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.

[0038] The cover 9 has a second tray 92 and a sub-tray 93 that together with the first tray 91 constitute the supply tray 90. The upper surface of the second tray 92 and the upper surface of the sub-tray 93 are the remainder of the support surface 95.

[0039] The supply tray 90 has side guides 92A and 92B. The side guides 92A and 92B are positioned on the second tray 92 and are slidable in the front-rear direction. By sliding the side guides 92A and 92B toward and toward each other, they 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.

[0040] As shown in Figure 2, the left-end upper cover 20 is pivotably supported by the base member 39. The left-end upper cover 20 is pivotable between a closed position shown by a solid line in Figure 2 and an open position shown by a dashed line in Figure 2.

[0041] The left-end top cover 20 covers the first support surface 91S and the transport guide surface 34G when it is in the closed position shown by the solid line in Figure 2. The left-end top cover 20 opens the first support surface 91S and the transport guide surface 34G by moving to the open position shown by the dashed line in Figure 2.

[0042] <Second reading sensor> The lower chute 37 has a lower guide section 37G and a sensor housing section 37H. The lower guide section 37G is a downward-facing guide surface that extends upward to the right, with its left end facing the scoop guide 7 from above. The sensor housing section 37H is recessed upward from the middle of the lower guide section 37G in the left-right direction and extends in the width direction.

[0043] The cover 9 has a second reading sensor 3U. The second reading sensor 3U is an example of the "reading sensor" of the present invention. The second reading sensor 3U is a well-known image reading sensor that uses CIS, CCD, etc., similar to the first reading sensor 3A.

[0044] The lower chute 37 supports the second reading sensor 3U in the sensor housing 37H. The downward-opening opening in the sensor housing 37H is covered by the reading glass 37R. The second reading sensor 3U is located below the first support surface 91S.

[0045] <Conveying section and 1st to 3rd conveying guides> 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.

[0046] The conveying unit 4 includes a feeding roller 41, a separation roller 42, a separation pad 42A, and a holder 50.

[0047] 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 covered by the left end upper cover 20 and faces the first support surface 91S from above.

[0048] 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 51 centered on a drive axis X42 that extends in the width direction. The drive shaft 51 rotates around the rotation axis X42, thereby transmitting driving force to the separation roller 42 and causing it to rotate.

[0049] The separation pad 42A is swingably supported by the guide portion 34A, exposed on the transport guide surface 34G and facing the separation roller 42 from below. The separation pad 42A is pressed toward the separation roller 42 by a biasing spring.

[0050] As shown in Figure 3, the holder 50 has the drive shaft 51 inserted through it. Although not shown in the figure, the drive shaft 51 is rotatably supported around the rotation axis X42 by the left end upper cover 20. As a result, the holder 50 is supported by the left end upper cover 20 so that it can swing around the rotation axis X42.

[0051] The holder 50 covers the separation roller 42 from above, in front, and behind. The holder 50 extends to the right of the rotation axis X42 and rotatably supports the feed roller 41 at its right end. The holder 50 supports the gear train 41G that transmits driving force from the drive shaft 51 to the feed roller 41.

[0052] The transport unit 4 includes a drive source M1, a drive force transmission mechanism (not shown), a gear 4G, and a torque limiter 52.

[0053] The drive source M1 is a motor located on the rear side of the cover 9. The drive source M1 generates driving force by rotating in both forward and reverse directions, controlled by a control unit (not shown).

[0054] A power transmission mechanism (not shown) transmits the power from the power source M1 to the gear 4G and to the drive roller 43A of the first transport roller pair 43, the drive roller 45A of the second transport roller pair 45, and the discharge roller 47, which will be described later.

[0055] Gear 4G is located on the rear side of cover 9, and is positioned below and to the right of the rotation axis X42.

[0056] A transmission gear 51G is fixed to the rear end of the drive shaft 51. In Figure 3, the left end upper cover 20, which is in the closed position, is not shown, but the transmission gear 51G is meshed with gear 4G when the left end upper cover 20 is in the closed position. When the left end upper cover 20 moves to the open position shown by the dashed line in Figure 2, the drive shaft 51, holder 50, separation roller 42, feed roller 41, etc. also move together with the left end upper cover 20, and the transmission gear 51G separates from gear 4G.

[0057] As shown in Figure 3, the torque limiter 52 is interposed between the drive shaft 51 and the holder 50. When a torque below a set value is applied, the torque limiter 52 transmits that torque to the holder 50. However, when a torque exceeding the set value is applied, slippage occurs internally, and the torque is no longer transmitted to the holder 50.

[0058] With the left end upper cover 20 in the closed position, the drive shaft 51 rotates around the rotation axis X42 when the driving force transmitted from the drive source M1 is input from gear 4G to the transmission gear 51G.

[0059] As shown in Figure 2, when the drive source M1 rotates in the forward direction, the torque limiter 52 causes the holder 50 to rotate in accordance with the rotation of the drive shaft 51. This causes the holder 50 to swing so as to lower the feed roller 41. When the feed roller 41 comes into contact with the uppermost sheet SH supported on the first support surface 91S, the torque limiter 52 holds the holder 50 in that position due to slippage occurring inside it. As a result, the feed roller 41 presses the sheet SH supported on the support surface 95 downward.

[0060] In this case, the drive shaft 51 transmits driving force to the separation roller 42 to rotate the separation roller 42, and also transmits driving force to the feed roller 41 via the gear train 41G to rotate the feed roller 41. As a result, the feed roller 41 feeds the uppermost sheet SH supported on the support surface 95 in the feed direction DF1. The separation roller 42 transports the sheet SH fed by the feed roller 41. At this time, if there are multiple sheets SH fed by the feed roller 41, the separation roller 42 and the separation pad 42A separate them one by one and transport the sheets SH.

[0061] When the drive source M1 rotates in the reverse direction, the torque limiter 52 causes the holder 50 to rotate in the opposite direction to the drive shaft 51. This causes the holder 50 to oscillate, raising the feed roller 41.

[0062] The position of the feed roller 41 (41U) shown in Figures 2 and 5 is the upper limit position. When the feed roller 41 reaches the upper limit position, the torque limiter 52 holds the holder 50 in that position due to slippage occurring inside it.

[0063] 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 M1 when the feed roller 41 reaches the upper limit position. The torque limiter 52 holds the holder 50 in that position even after the drive source M1 has stopped.

[0064] As shown in Figure 2, the conveying unit 4 includes a first conveying roller pair 43, a first pressing member 44, a second pressing member 46, a second conveying roller pair 45, a discharge roller 47, and an elastic piece 48.

[0065] 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 first pressing member 44 is located directly above the reading surface 3B. The first pressing member 44 extends in the width direction directly above the reading surface 3B and to the left of the lower guide portion 37G. The first pressing member 44 is biased toward the reading surface 3B by a biasing spring.

[0066] The first transport guide 31 consists of a transport guide surface 34G and multiple ribs 20R that protrude downward from the back surface of the left end upper cover 20. The first transport guide 31 guides the sheet SH, which is supported on the support surface 95, to the left via the separation roller 42, then makes a U-turn downward, and guides it to the first transport roller pair 43.

[0067] The second transport guide 32 consists of a portion located to the left of the first pressing member 44 in the lower chute 37, and a guide surface formed inside the left side of the cover 9.

[0068] 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 to pass between the first pressing member 44 and the reading surface 3B, that is, above the first reading sensor 3A which is in the stationary reading position. The first pressing member 44 presses the sheet SH toward the reading surface 3B as it passes through.

[0069] The second pressing member 46 is held in the portion of the base frame 39 that faces the reading glass 37R from below. The second pressing member 46 extends in the width direction to the right of the scoop guide 7 and below the second reading sensor 3U. The second pressing member 46 is biased toward the reading glass 37R and the second reading sensor 3U by a biasing spring.

[0070] 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.

[0071] The elastic piece 48 is made of a highly rigid film. The elastic piece 48 is cantilevered to the right end of the lower guide section 37G and protrudes to the right, bending at a position to the right of the discharge roller 47 and sloping downward to the right.

[0072] 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.

[0073] The third transport guide 33 consists of the lower surface of the lower guide portion 37G, the lower surface of the reading glass 37R, the scoop guide 7, the portion of the base frame 39 located between the scoop guide 7 and the second pressing member 46 and facing the lower guide portion 37G from below, the second pressing member 46, the portion of the base frame 39 located between the second pressing member 46 and the discharge tray 96 and facing the lower guide portion 37G from below, and the like.

[0074] The third transport guide 33 scoops up the sheet SH passing over the reading surface 3B with the scoop guide 7 and guides it between the second pressing member 46 and the reading glass 37R, that is, below the second reading sensor 3U. The second pressing member 46 presses the sheet SH, which has been scooped up by the scoop guide 7, toward the reading glass 37R and the second reading sensor 3U. The third transport guide 33 then guides the sheet SH through the second transport roller pair 45, and further toward the discharge roller 47 and the elastic piece 48.

[0075] The cover 9 has a transport path P1 defined by the first to third transport guides 31 to 33. The transport path P1 extends to the left from the supply tray 90, then makes a downward U-turn to change direction, and then passes below the support surface 95 to the discharge tray 96.

[0076] The conveying unit 4 conveys the sheet SH, which has been fed by the feed roller 41, by making a downward U-turn along the conveying path P1, passing below the actuator 60 (described later), and then passing below the support surface 95.

[0077] <Locking member and unlocking rib> As shown in Figure 3, the transport unit 4 has two locking members 57. The front locking member 57 is pivotably supported on a support shaft 50A that protrudes forward from the front and right corner of the holder 50. The rear locking member 57 is pivotably supported on a support shaft 50B that protrudes rearward from the rear and right corner of the holder 50. Each locking member 57 protrudes radially outward from the support shafts 50A and 50B.

[0078] Figures 5 and 6 show the front locking member 57, while the rear locking member 57 is the same as the front locking member 57 and is therefore not shown.

[0079] As shown in Figures 5 and 6, the left-end upper cover 20 has two release ribs 29. In Figures 5 and 6, the front release rib 29 is shown, while the rear release rib 29 is the same as the front release rib 29 and is therefore not shown.

[0080] The front unlocking rib 29 is formed between two ribs 20R that position the front locking member 57 between them. The rear unlocking rib 29 is formed between two ribs 20R that position the rear locking member 57 between them.

[0081] Each release rib 29 extends in the front-rear direction at a position that is separated to the left and downward from the support shafts 50A and 50B.

[0082] As shown in Figure 5, when the holder 50 raises the feed roller 41 to its upper limit position, each locking member 57 is in a locked position that protrudes to the left above each unlocking rib 29.

[0083] As shown in Figure 6, each locking member 57 swings upward and moves to the unlocked position as the holder 50 lowers the feed roller 41 from its upper limit position, causing it to contact each unlocking rib 29.

[0084] In other words, each locking member 57 is in the locked position until the feed roller 41 feeds the sheet SH, and moves to the unlocked position when the feed roller 41 descends and feeds the sheet SH.

[0085] As shown in Figure 5, each locking member 57 returns to the locked position when the holder 50 returns the feed roller 41 to its upper limit position.

[0086] <Shutter> As shown in Figure 3, the transport unit 4 has two shutters 70. The front shutter 70 is located to the left of the front locking member 57 and support shaft 50A. The rear shutter 70 is located to the left of the rear locking member 57 and support shaft 50B.

[0087] Figures 5 and 6 show the front shutter 70, while the rear shutter 70 is the same as the front shutter 70 and is therefore not shown.

[0088] The front shutter 70 is supported so as to be able to pivot around the pivot axis X70 by a support shaft 70S mounted on two ribs 20R that position the front locking member 57 between them. The rear shutter 70 is supported so as to be able to pivot around the pivot axis X70 by a support shaft 70S mounted on two ribs 20R that position the rear locking member 57 between them.

[0089] The pivot axis X70 extends in the width direction at a position spaced to the left of each release rib 29 and slightly below each release rib 29. Furthermore, the pivot axis X70 is located almost directly above the downstream end 95D of the support surface 95. Although not shown in the illustration, the pivot axis X70 is located above the uppermost sheet SH when the maximum number of sheets SH are supported on the support surface 95.

[0090] As shown in Figures 7 and 8, each shutter 70 integrally includes a shaft support portion 77, a shutter body 71, and a lock receiving portion 78. In this embodiment, each shutter 70 is a resin molded product and is manufactured by injection molding of thermoplastic resin or the like.

[0091] The shaft support portion 77 is roughly block-shaped. A through hole 77H is formed in the shaft support portion 77 so as to penetrate it in the width direction. The through hole 77H is a round hole centered on the pivot axis X70, into which the support shaft 70S is inserted.

[0092] The shutter body 71 is connected to a portion of the lower surface of the shaft support portion 77 that is located to the left of the through hole 77H and protrudes downward.

[0093] The locking receiver portion 78 is connected to a portion of the upper surface of the shaft support portion 77 that is located to the left of the through hole 77H, and protrudes briefly upward.

[0094] As shown in Figure 4, two recesses 34D are recessed downwards on the downstream end 95D side of the support surface 95 on the transport guide surface 34G.

[0095] As shown in Figure 5, the shutter body 71 of each shutter 70 protrudes downward, with its lower end entering each recess 34D. The positions of each shutter 70 shown in Figure 5, and the positions of each shutter 70 shown by solid lines in Figure 6, are restricting positions that restrict the leading edge of the sheet SH inserted along the support surface 95.

[0096] As shown by the dashed lines in Figure 6, the shutter body 71 of each shutter 70 swings so that its lower end moves to the left, thereby separating its lower end upward from the recesses 34D and the transport guide surface 34G. The positions of each shutter 70 shown by the dashed lines in Figure 6 are retracted positions where they are moved away from the sheet SH being fed by the feed roller 41.

[0097] In other words, each shutter 70 swings between a restricted position and a retracted position around the pivot axis X70.

[0098] As shown in Figure 5, when the holder 50 raises the feed roller 41 to its upper limit position, each locking member 57 in the locked position has its tip in contact with the locking receiving portion 78, thereby restricting the swinging of each shutter 70 from the restricted position to the retracted position.

[0099] As shown in Figure 6, each locking member 57, which swings to the unlocked position when the holder 50 lowers the feed roller 41 from the upper limit position, separates its tip from the locking receiving portion 78, allowing each shutter 70 to swing from the restricted position to the retracted position.

[0100] The shutter 70 shown in Figures 7 and 8 is restricted by each locking member 57 in the locked position, and its orientation is based on the position when it is in the restricted position. The shutter 70 has six first restricting surfaces 71 (71A, 71B, 71C, 71D, 71E, 71F) and five second restricting surfaces 72 (72A, 72B, 72C, 72D, 72E).

[0101] Each first restricting surface 71 (71A to 71F) is a flat surface that is aligned vertically and faces to the right, i.e., upstream in the feeding direction DF1. When each shutter 70 is restricted by each locking member 57 in the locked position, each first restricting surface 71 (71A to 71F) extends along the vertical direction. In this embodiment, each first restricting surface 71 (71A to 71F) extends parallel to the vertical direction.

[0102] Each second restricting surface 72 (72A to 72E) is a flat surface facing downwards and located between each first restricting surface 71 (71A to 71F). When each shutter 70 is restricted by each locking member 57 in the locked position, each second restricting surface 72 (72A to 72E) extends along the horizontal direction. In this embodiment, each second restricting surface 72 (72A to 72E) extends parallel to the horizontal direction.

[0103] Of the two adjacent first restricting surfaces 71 in the vertical direction, if the one located above is designated as the first surface and the other as the second surface, the entire second surface is located to the left of the first surface, i.e., downstream in the feeding direction DF1, and the second restricting surface 72 located between the first and second surfaces is connected to the lower end of the first surface and the upper end of the second surface.

[0104] Specifically, the entirety of the first restricting surface 71B is located to the left of the first restricting surface 71A, and the second restricting surface 72A, located between the first restricting surface 71A and the first restricting surface 71B, is connected to the lower end of the first restricting surface 71A and the upper end of the first restricting surface 71B.

[0105] The entirety of the first restricting surface 71C is located to the left of the first restricting surface 71B, and the second restricting surface 72B, located between the first restricting surface 71B and the first restricting surface 71C, is connected to the lower end of the first restricting surface 71B and the upper end of the first restricting surface 71C.

[0106] The entirety of the first restricting surface 71D is located to the left of the first restricting surface 71C, and the second restricting surface 72C, located between the first restricting surface 71C and the first restricting surface 71D, is connected to the lower end of the first restricting surface 71C and the upper end of the first restricting surface 71D.

[0107] The entirety of the first restricting surface 71E is located to the left of the first restricting surface 71D, and the second restricting surface 72D, located between the first restricting surface 71D and the first restricting surface 71E, is connected to the lower end of the first restricting surface 71D and the upper end of the first restricting surface 71E.

[0108] The entirety of the first restricting surface 71F is located to the left of the first restricting surface 71E, and the second restricting surface 72E, located between the first restricting surface 71E and the first restricting surface 71F, is connected to the lower end of the first restricting surface 71E and the upper end of the first restricting surface 71F.

[0109] As shown in Figures 5 and 7, each first restricting surface 71 (71A to 71F) and each second restricting surface 72 (72A to 72E) can contact the leading edge of the sheet SH when the user inserts the sheet SH along the support surface 95 while each shutter 70 is in the restricting position.

[0110] Subsequently, when the feeding roller 41 feeds the sheet SH supported on the support surface 95, each shutter 70 swings to a retracted position as the first restricting surface 71 (71A~71F) and each second restricting surface 72 (72A~72E) are pushed by the sheet SH being fed, as shown by the dashed lines in Figure 6, thereby allowing the sheet SH to pass through.

[0111] The shutter 70 shown in Figures 9 and 10 is in the locked position, restricted by each locking member 57 in the locked position.

[0112] <Actuators and sensors> As shown in Figures 9 and 10, the cover 9 has an actuator 60 and a sensor 69 for detecting the presence or absence of a sheet SH supported on the support surface 95.

[0113] As shown in Figure 9, the actuator 60 has an actuator body 65, a pivot shaft 66, and a shielding portion 67. In this embodiment, the actuator 60 is a resin molded product in which the actuator body 65, pivot shaft 66, and shielding portion 67 are integrally formed, and is manufactured by injection molding of thermoplastic resin or the like.

[0114] The actuator body 65 is a flat plate shape extending in the vertical and horizontal directions. The oscillating shaft 66 is connected to the lower end of the actuator body 65 and extends in the width direction with respect to the oscillating axis X60. The shielding portion 67 is a plate-shaped piece that protrudes to the left from the oscillating shaft 66.

[0115] The pivot axis X60 is located downstream of the downstream end 95D of the support surface 95 in the feeding direction DF1. In other words, the pivot axis X60 is located downstream of the feeding roller 41 in the feeding direction DF1. The pivot axis X60 is located below the support surface 95 and above the lower guide portion 37G of the lower chute 37. The pivot axis X60 is located between the first pressing member 44 and the sensor housing portion 37H in the left-right direction.

[0116] Although not shown in the diagram, the actuator 60 is pivotable around the pivot axis X60 because the pivot shaft 66 is pivotably supported by the lower chute 37.

[0117] Sensor 69 is located near the shielding portion 67. Sensor 69 is a photointerrupter having an optical path 69P from a light-emitting portion (not shown) to a light-receiving portion. Sensor 69 detects the shielding and opening of the optical path 69P by the shielding portion 67 of actuator 60. Sensor 69 transmits a detection signal corresponding to the shielding and opening of the optical path 69P to a control unit (not shown).

[0118] The actuator 60 is biased in the clockwise direction in Figure 9 by a torsion coil spring 60S. The actuator body 65 has a stopper 62 and a contact surface 61.

[0119] The stopper 62 is a forward-facing end face formed on the actuator body 65 at a position to the right and above the pivot axis 66. The initial position of the actuator 60 is determined when the stopper 62 abuts against the left wall of the sensor housing 37H due to the biasing force of the torsion coil spring 60S. In this state, the shielding portion 67 shields the optical path 69P.

[0120] The contact surface 61 is a forward-facing end face located above the stopper 62 on the actuator body 65. The contact surface 61 extends to the upper end of the actuator body 65, tilting to the left as it moves upward.

[0121] As shown in Figure 4, with the actuator 60 in its initial position, the upper portion of the actuator body 65 protrudes upward from the upper chute 34 at a position slightly forward of the rear recess 34D.

[0122] As shown in Figure 9, with the actuator 60 in its initial position, the contact surface 61 is located upstream of the downstream end 95D of the support surface 95 in the feeding direction DF1. The contact surface 61 can contact the leading edge of the sheet SH inserted along the support surface 95. The initial position of the actuator 60 is the position when the contact surface 61 is not in contact with the leading edge of the sheet SH inserted along the support surface 95.

[0123] When the contact surface 61 is not in contact with the leading edge of the sheet SH inserted along the support surface 95, it is located upstream in the feeding direction DF1 from the first restricting surface 71A, which is located at the uppermost position in each shutter 70 that is in a restricting position.

[0124] As shown by the solid line in Figure 10, the contact surface 61 is pushed to the left and swings when it comes into contact with the tip of the sheet SH inserted along the support surface 95. As a result, after the contact surface 61 swings in contact with the tip of the sheet SH inserted along the support surface 95, it is located downstream in the feeding direction DF1 from the first restricting surface 71A, which is located at the uppermost position in each shutter 70 that is in the restricting position. In addition, the shielding portion 67 opens the optical path 69P.

[0125] As shown by the dashed line in Figure 10, the actuator 60 swings further and retracts from the sheet SH as the contact surface 61 is pressed against the sheet SH being fed by the feed roller 41.

[0126] As shown in Figure 9, when the shielding portion 67 is blocking the optical path 69P, the sensor 69 detects that there is no sheet SH supported on the support surface 95, based on the fact that the actuator 60 is in its initial position.

[0127] As shown in Figure 10, when the shielding portion 67 opens the optical path 69P, the sensor 69 detects that there is a sheet SH supported on the support surface 95 based on the fact that the actuator 60 has swung from its initial position.

[0128] <Image reading operation of the sheet supported in the supply tray> When the image reading unit 3 reads an image of the sheet SH supported on the support surface 95, the control unit (not shown), which receives an instruction to start the image reading operation, determines whether or not the sheet SH is supported on the support surface 95 based on the detection signal transmitted from the sensor 69.

[0129] If the control unit (not shown) determines that there is no sheet SH supported on the support surface 95, it displays a message on the display screen of the operation panel 8P indicating that there is no sheet SH on the support surface 95, and waits until a sheet SH is supported on the support surface 95.

[0130] When the control unit (not shown) determines that there is a sheet SH supported on the support surface 95, it rotates the drive source M1 in the forward direction to operate the transport unit 4.

[0131] 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.

[0132] As a result, as shown in Figure 6, the holder 50 swings down 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 on the support surface 95. At this time, the feed roller 41 presses downward on the uppermost sheet SH supported on the support surface 95. In addition, each locking member 57 swings to the unlocked position, allowing each shutter 70 to swing from the restricted position to the retracted position.

[0133] As shown in Figure 2, the feeding roller 41 feeds the uppermost sheet SH, supported on the support surface 95, in the feeding direction DF1. The separating roller 42 and separating pad 42A separate the sheets SH one by one if there are multiple sheets SH being fed by the feeding roller 41, and transport the sheets SH toward the first transport roller pair 43.

[0134] Next, the first transport roller pair 43 transports the sheet SH, guided by the first transport guide 31 and the second transport guide 32, to pass over the first reading sensor 3S, which is in a stationary reading position. The first reading sensor 3S reads the image of the downward-facing surface of the sheet SH as it passes through the reading surface 3B. The downward-facing surface of the sheet SH as it passes through the reading surface 3B is the surface that was facing upward when the sheet SH was supported by the support surface 95.

[0135] Furthermore, the first transport roller pair 43 transports the sheet SH toward the second reading sensor 3U. When the image reading unit 3 reads images of both sides of the sheet SH, the second reading sensor 3U reads the image of the upward-facing side of the sheet SH that has been picked up by the scoop guide 7. The upward-facing side of the sheet SH that has been picked up by the scoop guide 7 is the side that was facing downward when the sheet SH was supported by the support surface 95.

[0136] In other words, the second reading sensor 3U reads an image of the upward-facing surface of the sheet SH as it moves towards the discharge tray 96 after making a U-turn along the transport path P1.

[0137] 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.

[0138] 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.

[0139] When the image reading operation of sheet SH is completed, the control unit (not shown) briefly reverses the rotation of the drive source M1. As a result, as shown in Figure 5, the holder 50 swings so that the feed roller 41 rises to the upper limit position. In addition, each locking member 57 swings to the locked position and its tip contacts the lock receiving portion 78, thereby restricting the swing of each shutter 70 from the restricted position to the retracted position.

[0140] <Effects and Effects> In the image reading device 1 of the embodiment, as shown in Figures 7 and 8, if one of the two adjacent first restricting surfaces 71 in the vertical direction is designated as the first surface and the other as the second surface, the entire second surface is located downstream of the first surface in the feeding direction DF1, and the second restricting surface 72 located between the first and second surfaces connects the lower end of the first surface and the upper end of the second surface. This relationship means that each first restricting surface 71 (71A to 71F) and each second restricting surface 72 (72A to 72E) forms a stepped slope, and that this stepped slope extends so as it approaches the support surface 95 that it shifts downstream in the feeding direction DF1.

[0141] With this configuration, as shown in Figures 5 and 7, each first restricting surface 71 (71A to 71F) can reliably restrict the sheet SH inserted along the support surface 95 by guiding the tip of the sheet SH downward so that it approaches the support surface 95, regardless of whether the tip of the sheet SH is curled upward or not.

[0142] Furthermore, each second restricting surface 72 (72A to 72E) can hold down the tip of the sheet SH, which has an upward-curling tip, when it is inserted along the support surface 95, thereby preventing the tip of the sheet SH from rising.

[0143] Therefore, the image reading device 1 of the embodiment can reliably align the tip of the sheet SH even when the sheet SH, whose tip is curled upward, is inserted along the support surface 95.

[0144] Furthermore, in this image reading device 1, as shown in Figure 9, the contact surface 61 of the actuator 60 is located upstream in the feeding direction DF1 from the uppermost first restricting surface 71A in each shutter 70 that is in the restricting position, when it is not in contact with the leading edge of the sheet SH inserted along the support surface 95. As shown by the solid line in Figure 10, the contact surface 61 is located downstream in the feeding direction DF1 from the uppermost first restricting surface 71A in each shutter 70 that is in the restricting position, when it has come into contact with the leading edge of the sheet SH inserted along the support surface 95. Then, as shown by the dashed line in Figure 10, the actuator 60 swings further and retracts from the sheet SH as the contact surface 61 is pushed by the sheet SH being fed by the feeding roller 41. With this configuration, even when a sheet SH with an upward-curling tip is inserted along the support surface 95, the effects of the first restricting surfaces 71 (71A to 71F) and second restricting surfaces 72 (72A to 72E) of each shutter 70 prevent the tip of the sheet SH from rising along the contact surface 61 of the swinging actuator 60. As a result, the actuator 60 can swing reliably when pushed by the sheet SH, and the sensor 69 can accurately detect the presence or absence of the sheet SH supported on the support surface 95.

[0145] Furthermore, in this image reading device 1, as shown in Figure 2, the transport unit 4 transports the sheet SH fed by the feed roller 41 by making a downward U-turn so that it passes below the actuator 60 and then below the support surface 95. The second reading sensor 3U is located below the first support surface 91S and reads the image of the upward-facing surface of the sheet SH after the U-turn. With this configuration, although the layout of each shutter 70 and actuator 60 is greatly constrained by the second reading sensor 3U, the actuator 60 can swing with high reliability by being pushed by the sheet SH inserted along the support surface 95 due to the effects of each first restricting surface 71 (71A~71F) and each second restricting surface 72 (72A~72E) of each shutter 70, and as a result the sensor 69 can accurately detect the presence or absence of the sheet SH supported by the support surface 95.

[0146] Furthermore, in this image reading device 1, each locking member 57 remains in the locked position until the feed roller 41 feeds the sheet SH, as shown in Figure 5, and swings to the unlocked position when the feed roller 41 feeds the sheet SH, as shown in Figure 6. With this configuration, each shutter 70 is reliably maintained in the restricted position by each locking member 57 until the feed roller 41 feeds the sheet SH. As a result, each shutter 70 can reliably align the leading edge of the sheet SH inserted along the support surface 95.

[0147] Furthermore, in this image reading device 1, as shown in Figure 7, when each shutter 70 is restricted by each locking member 57 in the locked position, each first restricting surface 71 (71A to 71F) extends along the vertical direction. With this configuration, each shutter 70 can align the leading edge of the sheet SH inserted along the support surface 95 with greater reliability.

[0148] 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.

[0149] 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.

[0150] In the embodiment, when each shutter 70 is restricted by each locking member 57 in the locked position, each first restricting surface 71 extends parallel to the vertical direction; however, the present invention is not limited to this configuration. For example, the present invention also includes a configuration in which, when each shutter is restricted by each locking member in the locked position, each first restricting surface extends such that it intersects the vertical direction at an angle of a few degrees or less. [Explanation of Symbols]

[0151] 1...Sheet feeding device (image reading device), SH...Sheet 95...Support surface, 90...Supply tray DF1...feeding direction, 41...feeding roller 70...Shutter, 71...First restricted area 72...Second regulatory surface, X60...Oscillating axis 60...Actuator, 61...Contact surface 69...Sensor, 4...Conveyor unit 3U...Reading sensor (second reading sensor), 57...Locking member

Claims

1. A supply tray having a support surface for supporting the sheet, 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 shutter that swings between a restricting position that restricts the leading edge of the sheet inserted along the support surface and a retracted position that moves away from the sheet being fed by the feed roller, A sheet feeding device equipped with, The shutter has a plurality of first restricting surfaces and at least one second restricting surface that can contact the leading edge of the sheet inserted along the support surface when the shutter is in the restricting position, Each of the first regulating surfaces is arranged vertically and faces upstream in the feeding direction. The second restricting surface is a surface located between each of the first restricting surfaces and facing downwards. If, of the two adjacent first restricting surfaces in the vertical direction, the one located above is designated as the first surface and the other as the second surface, A sheet feeding device characterized in that the entirety of the second surface is located downstream of the first surface in the feeding direction, and the second regulating surface located between the first surface and the second surface is connected to the lower end of the first surface and the upper end of the second surface.

2. An actuator that is located downstream of the feeding roller in the feeding direction and below the support surface and is capable of swinging about a pivot axis extending in the width direction, the actuator having a contact surface that contacts the tip of the sheet inserted along the support surface, A sensor that detects the presence or absence of a sheet supported on the support surface based on the position of the actuator, Equipped with, The contact surface is located upstream in the feeding direction from the first restricting surface, which is located at the uppermost position in the shutter, when it is not in contact with the leading edge of the sheet inserted along the support surface. The contact surface, in the state after contacting the leading edge of the sheet inserted along the support surface, is located downstream in the feeding direction from the first restricting surface, which is located at the uppermost position in the shutter at the restricting position. The sheet feeding device according to claim 1, wherein the contact surface is pressed against the sheet fed by the feeding roller, causing the actuator to swing further and retract from the sheet.

3. A conveying unit that conveys the sheet fed by the feed roller by making a U-turn downwards so that it passes below the actuator and then below the support surface, A reading sensor located below the support surface reads an image of the upward-facing surface of the sheet after it has made a U-turn. The sheet feeding device according to claim 2, comprising:

4. The locking member moves between a locked position that restricts the swinging of the shutter from the restricted position to the retracted position, and an unlocked position that allows the swinging of the shutter from the restricted position to the retracted position. The sheet feeding device according to any one of claims 1 to 3, wherein the locking member is in the locked position until the feeding roller feeds a sheet, and switches to the unlocked position when the feeding roller feeds a sheet.

5. The sheet feeding device according to claim 4, wherein each of the first restricting surfaces extends along the vertical direction when the shutter is restricted by the locking member in the locked position.

Images