Sheet detection device and image reading device

Abstract

To provide a sheet detection device capable of suppressing reduction in detection accuracy of a sensor, and to provide an image reading device.SOLUTION: In a sheet detection device 6, an actuator 100 has a rotary shaft 103, a contact part 101, and a detected part 105 and rotates between a first position and a second position. An energization member 60 energizes the actuator 100 toward the first position. A support 37 has a first regulation part 71 while rotatably supporting the rotary shaft 103. A sensor 69 detects presence / absence of a sheet SH based on a position of the detected part 105, when the actuator 100 rotates toward the second position from the first position. A sheet contact face 112 capable of abutting on a tip of the sheet SH while being directed to the upstream in a conveyance direction DT1 in a state where the actuator 100 is at the first position, and a first regulated face 111 abutting on the first regulation part 71 in the state where the actuator 100 is at the first position are formed in the contact part 101.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a sheet detecting device and an image reading device. [Background technology]

[0002] Patent Document 1 discloses an example of a conventional sheet detection device. In this sheet detection device, an actuator has a rotation shaft, a sheet detection lever, a stopper lever, and a light-blocking flag. The sheet detection lever extends radially outward from the rotation shaft. The stopper lever extends radially outward from the rotation shaft at a position spaced apart from the sheet detection lever in the direction in which the rotation shaft extends. The light-blocking flag extends radially outward from the rotation shaft at a position spaced apart from the sheet detection lever and the stopper lever in the direction in which the rotation shaft extends.

[0003] The actuator rotates between a standby position and a pressed position. The standby position of the actuator is a position where the sheet detection lever can contact the leading edge of a sheet moving in the conveying direction. The pressed position of the actuator is a position where the sheet detection lever is pressed by the sheet moving in the conveying direction and rotates downstream in the conveying direction to allow the sheet to pass.

[0004] The torsion spring exerts a biasing force that biases the actuator toward a standby position. The support member rotatably supports the rotation shaft. The support member has an abutment surface. The abutment surface abuts against the stopper lever, thereby stopping the actuator, which receives the biasing force of the torsion spring, at the standby position.

[0005] The sheet detection sensor detects the presence or absence of a sheet based on the position of the light-shielding flag when the actuator rotates from the standby state position to the pressed state position against the biasing force of the torsion spring. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2017-81717 Summary of the Invention [Problem to be solved by the invention]

[0007] In the above-mentioned conventional sheet detection device, when the sheet detection lever is no longer pressed by the sheet, the actuator rotates from the pressed position toward the standby position due to the force of the torsion spring, and when it reaches the standby position, the stopper lever collides with the abutment surface.

[0008] At this time, the stopper lever rebounds in reaction to the collision, attempting to rotate the pivot shaft in the opposite direction, and the sheet detection lever, which is generally larger in size and mass than the stopper lever, attempts to twist the pivot shaft, which then attempts to release the twist. Due to these behaviors, when the actuator reaches the standby position, this sheet detection device makes it difficult to prevent the position of the light-blocking flag from shifting relative to the sheet detection sensor, making chattering of the sheet detection sensor more likely to occur, and as a result, it may become difficult to prevent a decrease in the detection accuracy of the sheet detection sensor.

[0009] The present invention has been made in view of the above-described conventional circumstances, and has an object to provide a sheet detection device and an image reading device that can suppress a decrease in the detection accuracy of a sensor. [Means for solving the problem]

[0010] The sheet detection device of the present invention is an actuator having a rotation shaft, a contact portion extending from the rotation shaft in a radially outward direction of the rotation shaft, and a detected portion extending from the rotation shaft in the radially outward direction at a position spaced from the contact portion in the direction in which the rotation shaft extends, wherein the actuator rotates between a first position where the contact portion can contact the leading edge of a sheet proceeding in a conveying direction, and a second position where the contact portion is pressed by the sheet and rotates downstream in the conveying direction to allow the sheet to pass; a biasing member that exerts a biasing force that biases the actuator toward the first position; a support body that rotatably supports the rotation shaft, the support body having a first restriction portion that abuts and stops the actuator that receives the biasing force at the first position; a sensor that detects the presence or absence of the sheet based on the position of the detection target portion when the actuator rotates from the first position to the second position against the biasing force; Equipped with The abutment portion is characterized by having a sheet abutment surface that faces upstream in the conveying direction and can abut against the leading edge of the sheet when the actuator is in the first position, and a first regulated surface that abuts against the first regulating portion when the actuator is in the first position.

[0011] In the sheet detection device of the present invention, when the sheet contact surface of the contact portion is no longer pressed by the sheet, the actuator rotates from the second position toward the first position due to the biasing force of the biasing member, and when it reaches the first position, the first regulated surface of the contact portion collides with the first regulating portion.

[0012] At this time, the contact portion receives a reaction force of the collision via the first regulated surface and attempts to rebound, but because the sheet contact surface and the first regulated surface are formed on the same contact portion, twisting of the pivot shaft due to the rebound is unlikely to occur. As a result, this seat detection device can suppress deviation of the position of the detected portion relative to the sensor when the actuator reaches the first position, making it less likely for sensor chatter to occur.

[0013] Therefore, the sheet detecting device of the present invention can suppress a decrease in the detection accuracy of the sensor. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a perspective view of an image reading apparatus according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic partial cross-sectional view of the image reading device according to the embodiment. [Figure 3] FIG. 3 is a partial perspective view of the image reading apparatus according to the embodiment, showing a state in which the left-end upper cover, the feed roller, the separation roller, etc. have been removed. [Figure 4] FIG. 4 is a partial perspective view showing the lower chute, the actuator, the photointerrupter, the torsion coil spring, and the like. [Figure 5] FIG. 5 is a partial perspective view showing the lower chute, the actuator, the photointerrupter, the torsion coil spring, and the like. [Figure 6] FIG. 6 is a perspective view of the actuator. [Figure 7] FIG. 7 is a perspective view of the actuator. [Figure 8] FIG. 8 is a schematic partial cross-sectional view showing the AA cross section of FIG. 5, illustrating a state in which the actuator is in the first position. [Figure 9] FIG. 9 is a schematic partial cross-sectional view similar to FIG. 8, showing the actuator rotating from the first position to the second position. [Figure 10] FIG. 10 is a schematic partial cross-sectional view showing the cross section BB of FIG. 5, illustrating a state in which the actuator has rotated to the second position. [Figure 11] FIG. 11 is a schematic partial cross-sectional view similar to FIG. 10, showing a state in which the actuator is stopped by the second restricting portion. [Figure 12] FIG. 12 is a schematic partial cross-sectional view showing an enlarged essential part of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

[0016] (Example) As shown in Fig. 1, an image reading device 1 of the embodiment is an example of a specific aspect of the image reading device of the present invention. As shown in Fig. 2, a sheet detection device 6 provided in the image reading device 1 of the embodiment is an example of a specific aspect of the sheet detection device of the present invention.

[0017] In Fig. 1, the side of the operation panel 8P of the image reading device 1 is the front. The side to the left when facing the operation panel 8P is the left side. The front-rear, left-right, and up-down directions shown in Fig. 2 and subsequent figures are all shown corresponding to the directions shown in Fig. 1.

[0018] <Overall structure> As shown in FIG. 1, the image reading device 1 includes a main body 8 and a document cover 9. The main body 8 is a flat, roughly box-shaped body. An operation panel 8P, such as a touch panel, is located on the front of the main body 8. The main body 8 houses an image forming unit 5 in its lower portion. The image forming unit 5 forms an image on a sheet using an inkjet system, a laser system, or the like.

[0019] As shown in FIG. 2, the main body 8 has an upper surface provided with a document support surface 8A, a reading surface 8B, and a scoop guide 7.

[0020] The document support surface 8A is the upper surface of a large-area platen glass located on the top surface of the main body 8. The reading surface 8B is the upper surface of a platen glass that is located to the left of the document support surface 8A on the top surface of the main body 8 and extends in an elongated shape in the front-to-rear direction.

[0021] The scoop guide 7 is located between the document support surface 8A and the reading surface 8B, protrudes upward, and extends in an elongated shape in the front-rear direction.

[0022] The document support surface 8A supports a document to be scanned. The document to be scanned may be paper, a sheet such as an OHP sheet, a book, etc. The scanning surface 8B and the scoop guide 7 are used when the transport unit 4, which will be described later, is in operation.

[0023] The main body 8 accommodates the image reading unit 3 in its upper portion. The image reading unit 3 has a first reading sensor 3A and a scanning mechanism (not shown).

[0024] The first reading sensor 3A is a well-known image reading sensor that uses a CIS (Contact Image Sensor) or a CCD (Charge Coupled Device), and is elongated in the front-to-rear direction. The first reading sensor 3A is located below the document support surface 8A and the reading surface 8B.

[0025] When the image reading unit 3 reads an image of a document supported on the document support surface 8A, the first reading sensor 3A moves from below the left edge of the document support surface 8A to the right, i.e., in the sub-scanning direction, by operation of a scanning mechanism (not shown), and reads the image of the document in a line in the front-to-back direction, i.e., in the main scanning direction. When the first reading sensor 3A moves to below the right edge of the document support surface 8A, it finishes reading the image and returns to its standby position by operation of a scanning mechanism (not shown).

[0026] When the transport unit 4, which will be described later, is operated, the first reading sensor 3A moves to a stationary reading position below the reading surface 8B and remains stationary due to the operation of a scanning mechanism (not shown).

[0027] 1, the document cover 9 is located above the main body 8. The rear end of the document cover 9 is connected to the rear end of the main body 8 via a hinge (not shown). The document cover 9 is swingable around a swing axis X9 extending in the left-right direction.

[0028] When closed, the document cover 9 covers the top surface of the main body 8. Although not shown in the drawings, the user can swing the document cover 9 upward and backward around the swing axis X9, causing the document cover 9 to open the top surface of the main body 8. In this state, the user can place a document on the document support surface 8A and remove the document.

[0029] 2, the document cover 9 has a base frame 39, a lower chute 37, and an upper chute 34. The lower chute 37 is an example of the "support" of the present invention.

[0030] The lower surface of the base frame 39 forms the bottom surface of the document cover 9, and is large enough to cover the document support surface 8A and the reading surface 8B. The lower chute 37 is located above the left portion of the base frame 39. The upper chute 34 is located above the lower chute 37.

[0031] Although not shown, the front and rear ends of the lower chute 37 are attached to the front and rear ends of the left portion of the base frame 39. The front and rear ends of the upper chute 34 are also attached to the front and rear ends of the left portion of the base frame 39.

[0032] The base frame 39, the lower chute 37, and the upper chute 34 are each an integrally molded product made of a resin material. In this embodiment, the base frame 39, the lower chute 37, and the upper chute 34 are each manufactured by injection molding of a thermoplastic resin.

[0033] <Supply tray and discharge tray> 1 and 2, the document 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 document cover 9. The discharge tray 96 is located below the supply tray 90.

[0034] 2, the upper surface of the right portion of the base frame 39 forms a discharge tray 96. The discharge tray 96 supports the sheet SH that has had its image read and is discharged.

[0035] The supply tray 90 has a sheet support surface 94. The sheet support surface 94 supports the sheets SH in a stacked state before the images are read.

[0036] In this embodiment, an object whose image is read using the document support surface 8A is referred to as a document, and an object whose image is read while being supported on the sheet support surface 94 and transported by the transport unit 4 is referred to as a sheet SH. The document and the sheet SH may be substantially the same thing.

[0037] The seat support surface 94 extends so as to slope gently downward to the left and also extends in the front-to-rear direction. The width direction of the seat support surface 94 is the front-to-rear direction. In this embodiment, one side of the width direction is the front, and the other side of the width direction is the rear.

[0038] The conveying direction DT1 for conveying the sheet SH supported on the sheet supporting surface 94 to the discharge tray 96 is leftward from the sheet supporting surface 94 to the left side of the document cover 9, makes a downward U-turn at the left side of the document cover 9 to change direction, and then turns rightward as the sheet SH passes through the reading surface 8B and the scooping guide 7 and reaches the discharge tray 96. The conveying direction DT1 is perpendicular to the width direction.

[0039] As shown in FIGS. 2 and 3, a downstream end 94D of the sheet support surface 94 in the transport direction DT1 is located between the left side surface of the document cover 9 and the center in the left-right direction.

[0040] The upper chute 34 integrally includes 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.

[0041] The first tray 91 extends to the left with a gentle downward slope. The upper surface of the first tray 91 forms a first support surface 91A. The first tray 91 forms part of the supply tray 90. The first support surface 91A is part of the sheet support surface 94, and includes a downstream end 94D of the sheet support surface 94.

[0042] The guide portion 34A extends gently upward to the left, and then curves downward. The upper surface of the guide portion 34A forms a conveyance guide surface 34G.

[0043] The document cover 9 has a second tray 92 and a sub-tray 93 which, together with the first tray 91, constitute a supply tray 90. The top surfaces of the second tray 92 and the sub-tray 93 are the remaining portions of a sheet support surface 94.

[0044] <Second reading sensor> 2, the lower chute 37 has a lower guide portion 37G and a recessed portion 70. The upstream end of the lower guide portion 37G in the conveying direction DT1 faces the scoop guide 7 from above. The lower guide portion 37G extends so as to slope upward along the conveying direction DT1. The recessed portion 70 is recessed upward from a middle portion of the lower guide portion 37G in the conveying direction DT1 and extends in the width direction.

[0045] The document cover 9 has a second reading sensor 3B. The second reading sensor 3B is an example of the "reading unit" of the present invention. The lower chute 37 supports the second reading sensor 3B while it is housed in a recess 70. The opening of the recess 70 that opens downward is closed by the reading glass 37R.

[0046] The second reading sensor 3B is located downstream of the scoop guide 7 in the conveying direction DT1 within the document cover 9. Like the first reading sensor 3A, the second reading sensor 3B is a well-known image reading sensor that uses a CIS, a CCD, or the like.

[0047] <Conveying section and first to third conveying guides> The document 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 and the first to third transport guides 31 to 33 are located inside the left portion of the document cover 9. The base frame 39, the lower chute 37, and the upper chute 34, together with a sheet metal frame (not shown), support the transport section 4.

[0048] The transport section 4 includes a feed roller 41, a separation roller 42, a separation pad 42A, a first transport roller pair 43, a first document holder 44, a second document holder 46, a second transport roller pair 45, a discharge roller 47, and an elastic piece 48.

[0049] The feeding roller 41 is located upstream of the downstream end 94D of the sheet supporting surface 94 in the conveying direction DT1, and faces the first supporting surface 91A from above.

[0050] The separation roller 42 is located downstream of the downstream end 94D of the sheet support surface 94 in the conveying direction DT1, and faces the conveying guide surface 34G from above.

[0051] The separation pad 42A is exposed on the conveying guide surface 34G and is supported by the guide portion 34A so as to be able to swing, facing the separation roller 42 from below. The separation pad 42A is pressed toward the separation roller 42 by a biasing spring.

[0052] The first conveying roller pair 43 is located on the left side of the document cover 9, close to the top surface of the main body 8. The first document holder 44 extends in the width direction at a position directly above the reading surface 8B and to the left of the lower guide portion 37G. The first document holder 44 is biased toward the reading surface 8B by a biasing spring.

[0053] The first conveying guide 31 is made up of a conveying guide surface 34G and a rib protruding downward from the rear surface of the left-end upper cover 98. The first conveying guide 31 guides the sheet SH supported on the sheet supporting surface 94 to the first conveying roller pair 43.

[0054] The second conveying guide 32 is made up of a portion of the lower chute 37 located to the left of the first document holder 44, a guide surface formed inside the left side surface of the document cover 9, and the like.

[0055] The second conveying guide 32 guides the sheet SH from the first conveying roller pair 43 to the reading surface 8B at an incline downward, and then guides the sheet SH to pass between the first document holder 44 and the reading surface 8B, i.e., above the first reading sensor 3A at the stationary reading position. The first document holder 44 presses the sheet SH passing over the reading surface 8B toward the reading surface 8B.

[0056] The second document holder 46 is held in a portion of the base frame 39 facing the reading glass 37R from below. The second document holder 46 extends in the width direction at a position downstream of the scoop guide 7 in the conveying direction DT1 and below the second reading sensor 3B. The second document holder 46 is biased toward the reading glass 37R and the second reading sensor 3B by a biasing spring.

[0057] The second conveying roller pair 45 is located above and to the left of the left end of the discharge tray 96. The upper drive roller 45A of the second conveying roller pair 45 is rotatably supported by a portion of the lower guide portion 37G located on the downstream end side in the conveying direction DT1.

[0058] The discharge roller 47 is located above the left edge of the discharge tray 96 and slightly shifted to the left from 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 conveying roller pair 45.

[0059] The elastic piece 48 is made of a highly rigid film. The elastic piece 48 is cantilevered at the downstream end of the lower guide portion 37G in the conveying direction DT1. The elastic piece 48 protrudes to the right so as to overlap with the upper portion of the discharge roller 47 when viewed along the width direction. The elastic piece 48 is bent at a position to the right of the discharge roller 47 and inclined downward to the right.

[0060] Although not shown, the conveying section 4 has a plurality of discharge rollers 47 and a plurality of elastic pieces 48, and the discharge rollers 47 and the elastic pieces 48 are arranged alternately in the width direction.

[0061] The third conveying guide 33 comprises the underside of the lower guide portion 37G, the underside of the reading glass 37R, the scoop guide 7, a portion located between the scoop guide 7 and the second document holder 46 on the base frame 39 and facing the lower guide portion 37G from below, the second document holder 46, and a portion located between the second document holder 46 and the discharge tray 96 on the base frame 39 and facing the lower guide portion 37G from below.

[0062] The third conveyance guide 33 uses the scoop guide 7 to scoop up the sheet SH passing over the reading surface 8B and guide it to pass between the second document holder 46 and the reading glass 37R, i.e., below the second reading sensor 3B. The second document holder 46 presses the sheet SH scooped up by the scoop guide 7 toward the reading glass 37R and the second reading sensor 3B. The third conveyance guide 33 then guides the sheet SH to pass through the second conveyance roller pair 45, and further to the discharge roller 47 and the elastic piece 48.

[0063] The document cover 9 has a transport path P1 defined by the first to third transport guides 31 to 33. The transport path P1 extends leftward from the supply tray 90, then makes a downward U-turn to change direction, and then extends to the discharge tray 96.

[0064] <Sheet detection device> As shown in FIGS. 2 and 3, the image reading device 1 includes a sheet detection device 6 for detecting the presence or absence of a sheet SH supported on the sheet support surface 94 of the supply tray 90.

[0065] 4 and 5, the sheet detection device 6 includes an actuator 100, a torsion coil spring 60, and a photointerrupter 69 in the lower chute 37. The torsion coil spring 60 is an example of the "biasing member" of the present invention. The photointerrupter 69 is an example of the "sensor" of the present invention.

[0066] <Actuator> As shown in FIGS. 5 to 8, the actuator 100 has a rotation shaft 103, a contact portion 101, and a detected portion 105.

[0067] 6 and 7, the rotating shaft 103 is a substantially cylindrical shape centered on a rotation axis X100 extending in the width direction. One end portion 103A and the other end portion 103B of the rotating shaft 103 in the width direction have a smaller diameter than a middle portion 103C of the rotating shaft 103 in the width direction.

[0068] The contact portion 101 is plate-shaped and extends from approximately the center in the width direction of the intermediate portion 103C of the rotating shaft 103 in the radially outward direction of the rotation axis X100 of the rotating shaft 103. The specific configuration of the contact portion 101 will be described in detail later.

[0069] The detected portion 105 extends in the direction in which the rotation shaft 103 extends from the abutting portion 101, i.e., in the radially outward direction of the rotation axis X100 from the rotation shaft 103 at a position spaced apart in the width direction. The detected portion 105 extends in a direction different from the direction in which the abutting portion 101 extends from the other end side in the width direction of the intermediate portion 103C of the rotation shaft 103.

[0070] The actuator 100 is a one-piece molded product made of a resin material. In this embodiment, the actuator 100 is manufactured by injection molding of a thermoplastic resin.

[0071] <Lower chute bearing and sensor holder> As shown in FIGS. 4, 5 and 8, the lower chute 37 has walls 73, 74, and 75 that form the recess .

[0072] The wall portion 73 extends in a generally flat plate shape in the vertical and width directions. The wall portion 73 defines the recess 70 from the left. As shown in FIG. 8, the lower edge of the wall portion 73 abuts against the left edge of the reading glass 37R from above. The upper edge of the wall portion 73 is located slightly to the right and below the downstream end 94D of the sheet support surface 94.

[0073] The wall portion 74 extends in a generally flat plate shape in the vertical and width directions at a position spaced to the right from the wall portion 73. The wall portion 74 defines the recessed portion 70 from the right. The lower edge of the wall portion 74 abuts against the right edge of the reading glass 37R from above.

[0074] The wall portion 75 extends in the left-right and width directions in a generally flat plate shape at a position spaced above the reading glass 37R. The wall portion 75 is connected to the upper edges of the walls 73 and 74. The wall portion 75 defines the recessed portion 70 from above.

[0075] 4, 5, and 8, the lower chute 37 has a first bottom wall 76 and a second bottom wall 77. The first bottom wall 76 is a portion of the bottom wall of the lower chute 37 that is located between the left edge of the reading glass 37R and the first document holder 44. The second bottom wall 77 is a portion of the bottom wall of the lower chute 37 that is located to the left of the first bottom wall 76 and above the first document holder 44. The second bottom wall 77 is located one step higher than the first bottom wall 76.

[0076] As shown in FIGS. 4 and 5, the lower chute 37 has bearing portions 76A and 76B and sensor holding portions 77A, 77B, and 77C.

[0077] The pivotal support portions 76A and 76B are formed on the upper surface side of the first bottom wall 76. The pivotal support portions 76A and 76B pivotally support one end 103A and the other end 103B of the rotation shaft 103 of the actuator 100, so that the lower chute 37 supports the rotation shaft 103 rotatably about the rotation axis X100.

[0078] The sensor holding portions 77A, 77B, and 77C are formed on the upper surface side of the second bottom wall 77. The sensor holding portions 77A, 77B, and 77C engage with the photointerrupter 69 and the board on which the photointerrupter 69 is mounted to position the photointerrupter 69 relative to the lower chute 37, whereby the lower chute 37 holds the photointerrupter 69.

[0079] <Torsion coil spring> 4, the torsion coil spring 60 has a coil portion 63, a first end portion 61, and a second end portion 62. The coil portion 63 is fitted onto the intermediate portion 103C of the rotation shaft 103.

[0080] 4 and 8, the first end 61 extends from one end of the coil portion 63 and is engaged with the first bottom wall 76 of the lower chute 37. The second end 62 extends from the other end of the coil portion 63 and is engaged with a spring engaging portion 106 of the abutment portion 101, which will be described later.

[0081] Torsion coil spring 60 exerts a biasing force F1 that biases actuator 100 to rotate counterclockwise on the page of FIG.

[0082] <Photointerrupter> 8 and 9, the photointerrupter 69 has an optical path 69P that extends from a light-emitting portion (not shown) to a light-receiving portion. The photointerrupter 69 detects opening and blocking of the optical path 69P by the detected portion 105 of the actuator 100. The photointerrupter 69 transmits a detection signal corresponding to the opening and blocking of the optical path 69P to a control portion (not shown).

[0083] <First and second restriction portions of the lower chute> The lower chute 37 has a first restricting portion 71 shown in FIGS. 4, 5, and 8 to 12, and a second restricting portion 72 shown in FIGS.

[0084] 5 and 12, the first restricting portion 71 is formed on a wall surface 73A of the wall portion 73 facing away from the recess 70. The wall surface 73A is a flat surface facing leftward and extending in the vertical and width directions.

[0085] The first restricting portion 71 has a first restricting surface 71A. The first restricting surface 71A is a flat surface that protrudes in a stepped manner from a wall surface 73A of the wall portion 73 downstream in the conveying direction DT1, i.e., toward the left, and extends vertically and widthwise while facing left. As shown in Fig. 5, the widthwise length of the first restricting surface 71A is significantly smaller than the widthwise length of the wall surface 73A.

[0086] 12, the distance by which the first regulating surface 71A protrudes in a stepped manner downstream in the conveying direction DT1 from the wall surface 73A is defined as LP1. The distance LP1 is preferably set so that the positional accuracy of the first regulating surface 71A can be easily increased and the wall portion 73 does not become too thick, and is, for example, approximately several tenths of a millimeter to several tenths of a millimeter. In this embodiment, as an example, the distance LP1 is 0.3 mm.

[0087] The first restricting surface 71A is capable of coming into contact with a first restricted surface 111 of the actuator 100, which will be described later.

[0088] 5 and 10, the second restricting portion 72 is the upper surface of a protrusion that protrudes upward in a stepped manner from the upper surface of the second bottom wall 77. The second restricting portion 72 is a flat surface that extends in the width direction and slopes slightly downward toward the left.

[0089] As shown in FIG. 11, the second restricting portion 72 is capable of coming into contact with a second restricted surface 122 of the actuator 100, which will be described later.

[0090] <Specific configuration of the contact portion of the actuator> As shown in FIGS. 5 and 6, the contact portion 101 of the actuator 100 is formed with a first regulated surface 111.

[0091] 12 by the biasing force F1 of the torsion coil spring 60, the actuator 100 rotates counterclockwise on the page of FIG. 12, and as a result, the first restricted surface 111 comes into flat contact with the first restricting surface 71A of the first restricting portion 71. As a result, the first restricting portion 71 abuts and stops the actuator 100, which receives the biasing force F1, at the first position shown in FIGS. 3 to 5, 8, and 12.

[0092] In other words, the torsion coil spring 60 exerts a biasing force F1 that biases the actuator 100 toward the first position. The first restricting surface 71A abuts against the first restricted surface 111 with their flat surfaces facing each other when the first restricting portion 71 abuts and stops the actuator 100 at the first position and while the actuator 100 is in the first position.

[0093] The position of the actuator 100 shown by the solid line in Figure 2 is also the first position. The actuator 100 shown in Figures 6 and 7 corresponds to the first position.

[0094] The following description of the shape of the contact portion 101 will be based on the state in which the actuator 100 is in the first position in the vertical and horizontal directions.

[0095] 6, 7, and 12, when the actuator 100 is in the first position, the contact portion 101 is located above the lower end 103E of the rotation shaft 103. The contact portion 101 has an upstream portion 101U and a downstream portion 101D.

[0096] The upstream portion 101U is located upstream in the conveying direction DT1 when the actuator 100 is at the first position. The downstream portion 101D is located downstream of the upstream portion 101U in the conveying direction DT1 when the actuator 100 is at the first position.

[0097] A boundary line BL1 between the upstream portion 101U and the downstream portion 101D extends vertically upward in a straight line from the upper end of the rotation shaft 103 when the actuator 100 is in the first position.

[0098] When the actuator 100 is in the first position, the detected part 105 extends leftward so as to be substantially perpendicular to the boundary line BL1.

[0099] The contact portion 101 is formed with the first regulated surface 111, the seat contact surface 112, the second regulated surface 122, and the spring locking portion .

[0100] The upstream portion 101U includes a first portion 110 having a seat contact surface 112 and a first regulated surface 111. The downstream portion 101D includes a second portion 120 having a second regulated surface 122 and a spring locking portion 106.

[0101] 6 and 7, the thickness of the upstream portion 101U and the thickness of the first portion 110 are the same as a first thickness T1. As shown in Fig. 7, the thickness of the downstream portion 101D and the thickness of the second portion 120 are the same as a second thickness T2. The first thickness T1 is greater than the second thickness T2.

[0102] The upper end of the sheet contact surface 112 is located at the upper right corner of the upstream section 101U and is rounded. The sheet contact surface 112 is a flat surface facing to the right, and is inclined so as to shift to the right as it extends downward.

[0103] 8, when the actuator 100 is in the first position, the sheet contact surface 112 faces upstream in the conveying direction DT1 and extends in the vertical direction so as to be substantially perpendicular to the sheet supporting surface 94. In this state, the sheet contact surface 112 can come into contact with the leading edge of a sheet SH that a user inserts in the conveying direction DT1 along the sheet supporting surface 94 up to the downstream end 94D of the sheet supporting surface 94.

[0104] In other words, the first position of the actuator 100 is a position where the contact portion 101 can contact the leading edge of the sheet SH moving in the conveying direction DT1.

[0105] When the actuator 100 is in the first position, the detected portion 105 interrupts the optical path 69P of the photointerrupter 69. The photointerrupter 69 transmits a detection signal corresponding to the interruption of the optical path 69P to a control unit (not shown).

[0106] 12, the first regulated surface 111 is located slightly downward from the lower end of the sheet contact surface 112. The first regulated surface 111 is a flat surface that faces rightward and extends vertically.

[0107] When viewed in the direction in which the rotation shaft 103 extends, i.e., the width direction, the first regulated surface 111 is inclined with respect to the sheet contact surface 112. Also, when viewed in the direction in which the rotation shaft 103 extends, the first regulated surface 111 is inclined with respect to an imaginary line K1 that passes through a center 111C of the first regulated surface 111 and a rotation axis X100 that is the center of the rotation shaft 103.

[0108] As shown in FIG. 7, the second regulated surface 122 is a flat surface that extends in the vertical direction and faces leftward at a position away from the center in the vertical direction on the boundary line BL1 to the left.

[0109] The spring locking portion 106 is a notch recessed to the right at a position below the second regulated surface 122. As shown in Fig. 12, the second end 62 of the torsion coil spring 60 is locked to the spring locking portion 106. A distance LS1 between the spring locking portion 106 and the second regulated surface 122 is smaller than a distance LS2 between the spring locking portion 106 and the rotation axis X100, which is the center of the rotation shaft 103.

[0110] In other words, the second end 62 of the torsion coil spring 60 is engaged with the spring engaging portion 106 of the abutment portion 101 at a position between the second regulated surface 122 and the pivot axis 103, and at a position closer to the second regulated surface 122 than the pivot axis X100.

[0111] The actuator 100 rotates between a first position shown in Fig. 8 and a second position shown in Fig. 10. The second position of the actuator 100 is a position where the contact portion 101 is pressed by the sheet SH and rotates downstream in the conveying direction DT1 to allow the sheet SH to pass.

[0112] As shown in Figure 9, when a user inserts a sheet SH along the sheet support surface 94 in the conveying direction DT1 up to the downstream end 94D of the sheet support surface 94, and the sheet contact surface 112 contacts the leading edge of the sheet SH and is pushed to the left, the actuator 100 rotates from the first position to the second position.

[0113] Then, the detected portion 105 opens the optical path 69P of the photointerrupter 69. The photointerrupter 69 transmits a detection signal corresponding to the opening of the optical path 69P to a control unit (not shown).

[0114] That is, the photointerrupter 69 detects the presence or absence of the sheet SH based on the position of the detected portion 105 when the actuator 100 rotates from the first position to the second position against the biasing force F1 of the torsion coil spring 60. In this way, the sheet detecting device 6 detects the presence or absence of the sheet SH supported on the sheet supporting surface 94 of the supply tray 90.

[0115] The position of the actuator 100 indicated by the two-dot chain line in FIG. 2 corresponds to the position of the actuator 100 shown in FIG.

[0116] 10, when the conveying unit 4 is actuated and the sheet SH on the sheet support surface 94 is conveyed in the conveying direction DT1, the sheet contact surface 112 is pressed to abut against the downward surface of the conveyed sheet SH, causing the actuator 100 to rotate to the second position and allow the sheet SH to pass.

[0117] There are cases where a user tries to forcibly rotate the abutment portion 101. A specific example is when the user forcefully inserts the sheet SH along the sheet support surface 94. In this case, there is a risk that the actuator 100 will rotate from the second position to the opposite side from the first position. In such a case, as shown in FIG. 11 , the second regulated surface 122 abuts against the second regulating portion 72 at flat surfaces, causing the second regulating portion 72 to abut and stop the actuator 100.

[0118] <Image reading operation of a sheet supported on a supply tray> In the image reading device 1, when the image reading unit 3 reads an image of a sheet SH supported on the sheet support surface 94 of the supply tray 90, the control unit (not shown) receives an instruction to start the image reading operation and determines whether or not a sheet SH is supported on the sheet support surface 94 of the supply tray 90 based on a detection signal transmitted from the photointerrupter 69 of the sheet detection device 6.

[0119] If the control unit (not shown) determines that there is no sheet SH supported on the sheet support surface 94, it displays a message on the display screen of the operation panel 8P indicating that there is no sheet SH on the sheet support surface 94, and waits until a sheet SH is supported on the sheet support surface 94.

[0120] When the control unit (not shown) determines that there is a sheet SH supported on the sheet support surface 94, it activates the conveying unit 4. As a result, the conveying unit 4 conveys the sheet supported on the supply tray 90 along the conveying path P1 in the conveying direction DT1 and discharges the sheet toward the discharge tray 96.

[0121] More specifically, the feeding roller 41 feeds the sheets SH supported on the sheet supporting surface 94. If there are multiple sheets SH fed by the feeding roller 41, the separation roller 42 and the separation pad 42A separate the sheets SH one by one and convey the sheets SH toward the first conveying roller pair 43.

[0122] Next, the first conveying roller pair 43 conveys the sheet SH guided by the first conveying guide 31 and the second conveying guide 32, and passes it over the first reading sensor 3A, which is at a stationary reading position. The first reading sensor 3A reads an image of the downward-facing side of the sheet SH passing over the reading surface 8B. The downward-facing side of the sheet SH passing over the reading surface 8B is the side that faced upward when the sheet SH was supported on the sheet support surface 94.

[0123] Furthermore, the first conveying roller pair 43 conveys the sheet SH toward the second reading sensor 3B. When the image reading unit 3 reads images on both sides of the sheet SH, the second reading sensor 3B reads the image of the upward-facing side of the sheet SH scooped up by the scooping guide 7. The upward-facing side of the sheet SH scooped up by the scooping guide 7 is the side that faced downward when the sheet SH was supported on the sheet support surface 94.

[0124] In other words, the second reading sensor 3B reads an image of the upward surface of the sheet SH that advances toward the discharge tray 96 after making a U-turn along the conveying path P1.

[0125] Thereafter, the second conveying roller pair 45 conveys the sheet SH guided by the third conveying guide 33 toward the discharge roller 47 and the elastic piece 48. The discharge roller 47 and the elastic piece 48 discharge the sheet SH onto the discharge tray 96 while deforming the sheet SH into a corrugated shape.

[0126] At this time, the discharge roller 47 and the elastic piece 48 discharge the sheet SH onto the discharge tray 96 from a position higher than the nip position of the second conveying roller pair 45.

[0127] Thereafter, when the control unit (not shown) determines that there is no more sheet SH supported on the sheet support surface 94, it stops the conveying unit 4 and ends the image reading operation.

[0128] <Action and effect> In the sheet detection device 6 of the embodiment, as shown in Figure 12, when the sheet abutment surface 112 of the abutment portion 101 is no longer pressed by the sheet SH, the actuator 100 rotates from the second position toward the first position due to the biasing force F1 of the torsion coil spring 60, and when it reaches the first position, the first regulated surface 111 of the abutment portion 101 collides with the first regulating portion 71.

[0129] At this time, the contact portion 101 tries to rebound due to the reaction of the collision via the first regulated surface 111, but because the sheet contact surface 112 and the first regulated surface 111 are formed on the same contact portion 101, twisting of the pivot shaft 103 due to the rebound is unlikely to occur. As a result, the sheet detection device 6 can suppress deviation of the position of the detected portion 105 relative to the optical path 69P of the photointerrupter 69 when the actuator 100 reaches the first position, making it difficult for chattering of the photointerrupter 69 to occur.

[0130] Therefore, the sheet detecting device 6 of the embodiment can suppress a decrease in the detection accuracy of the photointerrupter 69.

[0131] Furthermore, in this sheet detection device 6, the first regulated surface 111 is inclined with respect to an imaginary line K1 that passes through a center 111C of the first regulated surface 111 and the rotation axis X100 when viewed in the direction in which the rotation shaft 103 extends, i.e., the width direction. The first regulating portion 71 has a first regulating surface 71A that abuts against the first regulated surface 111 with its flat surface against the first regulated surface 111 when the first regulating portion 71 abuts against and stops the actuator 100 at the first position. With this configuration, the reaction force FR1 generated when the first regulated surface 111 of the abutting portion 101 collides with the first regulating surface 71A of the first regulating portion 71 can be reduced compared to a configuration in which the first regulated surface 111 is parallel to the imaginary line K1 when viewed in the direction in which the rotation shaft 103 extends. As a result, the component force FR1A of the reduced reaction force FR1 that tends to rotate the actuator 100 toward the second position can also be reduced.

[0132] Furthermore, in this sheet detection device 6, the contact portion 101 is located above the lower end 103E of the rotation shaft 103 when the actuator 100 is in the first position. This configuration reduces the need to secure space below the rotation shaft 103 for the contact portion 101, making it easier to make the sheet detection device 6 smaller in size in the vertical direction.

[0133] Furthermore, in this sheet detecting device 6, the first regulated surface 111 is inclined with respect to the sheet contact surface 112 when viewed along the extending direction of the rotation shaft 103. With this configuration, the sheet contact surface 112 and the first regulated surface 111 are formed independently of each other on the same contact portion 101, which makes it easy to improve the positional accuracy of the first regulated surface 111.

[0134] Furthermore, in this sheet detection device 6, as shown in FIG. 11 , the lower chute 37 has a second restricting portion 72 that abuts against and stops the actuator 100 as it rotates from the second position toward the opposite side from the first position. The abutting portion 101 has a second restricted surface 122 that can abut against the second restricting portion 72. The abutment between the second restricted surface 122 and the second restricting portion 72 prevents the actuator 100 from rotating more than necessary from the second position toward the opposite side from the first position. This prevents the rotation shaft 103 from being excessively twisted or the detected portion 105 from colliding with the first bottom wall 76 of the lower chute 38, even if a user tries to forcibly rotate the abutting portion 101. As a result, this sheet detection device can prevent damage to the rotation shaft 103 and the detected portion 105.

[0135] 7, in the sheet detecting device 6, the first thickness T1 of the first portion 110 is greater than the second thickness T2 of the second portion 120. With this configuration, the contact area of ​​the sheet contact surface 112 with the sheet SH is increased to reduce the contact pressure with the sheet SH, thereby suppressing wear, and the first regulated surface 111 is suppressed from being damaged or worn due to a collision with the first regulating portion 71.

[0136] Furthermore, in this sheet detection device 6, the thickness of the upstream portion 101U is the same as the first thickness T1 of the first portion 110, and the thickness of the downstream portion 101D is the same as the second thickness T2 of the second portion 120. With this configuration, the strength of the upstream portion 101U of the abutting portion 101 that comes into contact with the sheet SH is maintained while the thickness of the downstream portion 101D that does not come into contact with the sheet SH is reduced, thereby reducing the material cost of the actuator 100.

[0137] 12, in the sheet detection device 6, the torsion coil spring 60 has a coil portion 63, a first end portion 61 that is engaged with the lower chute 37, and a second end portion 62 that is engaged with the contact portion 101. The second end portion 62 is engaged with the spring engaging portion 106 of the contact portion 101 at a position between the second regulated surface 122 and the rotation shaft 103 and closer to the second regulated surface 122 than the rotation axis X100. With this configuration, the torsion coil spring 60 biases the actuator 100 at a position away from the rotation shaft 103 in the radially outward direction of the rotation axis X100, thereby suppressing variations in the biasing force F1.

[0138] The image reading device 1 of the embodiment can suppress a decrease in the detection accuracy of the photointerrupter 69 by the action of the sheet detection device 6 described above.

[0139] In addition, in this image reading device 1, the lower chute 37 has a first restriction portion 71 formed on a wall surface 73A of a wall portion 73 that forms the recess 70. With this configuration, this image reading device 1 can be simplified by utilizing the existing wall portion 73 for the first restriction portion 71 without providing a new one. As a result, this image reading device 1 can be prevented from becoming larger.

[0140] Furthermore, in this image reading device 1, the first regulating surface 71A of the first regulating portion 71 protrudes in a stepped manner downstream in the transport direction DT1 from the wall surface 73A of the wall portion 73. This configuration makes it easy to improve the positional accuracy of the first regulating surface 71A of the first regulating portion 71.

[0141] Although the present invention has been described above with reference to the examples, it goes without saying that the present invention is not limited to the above examples and can be modified and applied as appropriate within the scope of the invention.

[0142] In the embodiment, the sheet detection device of the present invention is embodied as a sheet detection device 6 applied to an image reading device 1 having 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 having only an image reading function, or may be applied to an image forming device having an image forming function.

[0143] In the embodiment, the sensor is a photointerrupter 69, but the present invention is not limited to this configuration. For example, the sensor may be a contact sensor, or a non-contact sensor that uses magnetism, electromagnetic induction, ultrasonic waves, or the like.

[0144] In the embodiment, the sheet detecting device 6 detects the presence or absence of a sheet SH supported on the sheet supporting surface 94 of the supply tray 90, but the present invention is not limited to this configuration. For example, the sheet detecting device may detect the presence or absence of a sheet proceeding in the conveying direction at a predetermined position along the conveying path. [Explanation of symbols]

[0145] 6...sheet detection device, 1...image reading device 103...rotating shaft, 101...contact portion 105...detected part, 100...actuator DT1: conveying direction, SH: sheet 60... Urging member (torsion coil spring) F1...urging force, 37...support (lower chute) 71...first restricting portion, 69...sensor (photointerrupter) 112...seat contact surface, 111...first restricted surface 111C...Center of the first restricted surface X100...Center of rotation axis (rotation axis) K1: An imaginary line passing through the center of the first restricted surface and the center of the rotation shaft 71A...first restriction surface, 103E...lower end of rotation shaft 69P...optical path, 72...second restricting portion 122...Second regulated surface, 110...First part T1...first thickness, 120...second part T2: Second thickness, 101U: Upstream section 101D...downstream portion, 63...coil portion 61...first end, 62...second end 90...supply tray, 96...discharge tray P1: Conveyance path, 4: Conveyance section 3B...reading section (second reading sensor), 70...recess 73, 74, 75...wall section, 73A...wall surface

Claims

1. an actuator having a rotation shaft, a contact portion extending from the rotation shaft in a radially outward direction of the rotation shaft, and a detected portion extending from the rotation shaft in the radially outward direction at a position spaced from the contact portion in the direction in which the rotation shaft extends, the actuator rotating between a first position where the contact portion can contact the leading edge of a sheet proceeding in a conveying direction, and a second position where the contact portion is pressed by the sheet and rotates downstream in the conveying direction to allow the sheet to pass; a biasing member that exerts a biasing force that biases the actuator toward the first position; a support body that rotatably supports the rotation shaft, the support body having a first restriction portion that abuts and stops the actuator that receives the biasing force at the first position; a sensor that detects the presence or absence of the sheet based on the position of the detection target portion when the actuator rotates from the first position to the second position against the biasing force; Equipped with A sheet detection device characterized in that the abutment portion is formed with a sheet abutment surface facing upstream in the conveying direction and capable of abutting against the leading edge of the sheet when the actuator is in the first position, and a first regulated surface that abuts against the first regulating portion when the actuator is in the first position.

2. When viewed along a direction in which the rotation shaft extends, the first regulated surface is inclined with respect to an imaginary line passing through a center of the first regulated surface and a center of the rotation shaft, The sheet detection device according to claim 1 , wherein the first regulating portion has a first regulating surface that comes into flat contact with the first regulated surface when the first regulating portion abuts against the first position to stop the actuator.

3. 2. The sheet detecting device according to claim 1, wherein the contact portion is located above a lower end of the pivot shaft when the actuator is in the first position.

4. The sheet detecting device according to claim 1 , wherein the first regulated surface is inclined with respect to the sheet contact surface when viewed along the direction in which the rotation shaft extends.

5. the sensor is a photointerrupter that is held by the support and detects opening and blocking of an optical path by the detected portion, the support body has a second restriction portion that abuts against and stops the actuator when the actuator rotates from the second position to the opposite side from the first position, The sheet detecting device according to claim 1 , wherein the contact portion is formed with a second regulated surface that can come into contact with the second regulating portion.

6. The contact portion is plate-shaped, A sheet detection device as described in claim 5, wherein a first thickness of a first portion of the contact portion in which the sheet contact surface and the first regulated surface are formed is greater than a second thickness of a second portion of the contact portion in which the second regulated surface is formed.

7. the contact portion has an upstream portion that is located upstream in the conveying direction when the actuator is at the first position and that includes the first portion; a downstream portion that is located downstream of the upstream portion in the conveying direction when the actuator is at the first position and that includes the second portion, the thickness of the upstream portion is the same as the first thickness; The sheet detecting device according to claim 6 , wherein the thickness of the downstream portion is the same as the second thickness.

8. The biasing member includes a coil portion that is fitted around the rotation shaft; a first end portion extending from one end of the coil portion and anchored to the support; a second end portion extending from the other end of the coil portion and engaged with the abutment portion, The sheet detection device according to claim 5, wherein the second end is engaged with the abutment portion at a position between the second regulated surface and the pivot shaft and closer to the second regulated surface than the center of the pivot shaft.

9. a supply tray for supporting sheets before images are read; a sheet detecting device according to any one of claims 1 to 8, which detects the presence or absence of a sheet supported on the supply tray; a discharge tray positioned below the supply tray and supporting the sheet after image reading and discharged; a conveying path extending laterally from the supply tray, then making a downward U-turn and changing direction, and then extending to the discharge tray; a conveying section that conveys the sheet supported on the supply tray along the conveying path in the conveying direction and discharges the sheet toward the discharge tray; a reading unit that reads an image of an upward surface of a sheet that makes a U-turn along the conveying path and then proceeds toward the discharge tray; An image reading device comprising:

10. the support body has a lower chute having a recess for accommodating the reading unit, 10. The image reading device according to claim 9, wherein the lower chute has the first restricting portion formed on a wall surface of a wall portion that defines the recess, the wall surface facing away from the recess.

11. the first restricting portion has a first restricting surface that comes into flat contact with the first restricted surface when the first restricting portion abuts against the actuator at the first position, The image reading device according to claim 10 , wherein the first regulating surface protrudes in a stepped shape from the wall surface of the wall portion toward downstream in the transport direction.

Images