Image reader

Abstract

To provide an image reading apparatus capable of adjusting bending stress acting on a sheet.SOLUTION: An image reading apparatus includes a frame, a conveying roller, a reading section, a first guide member, a second guide member, a supporting section, and a locking section. The conveying roller conveys a sheet along a conveying path. The reading section is supported rotatably around, with respect to the frame, a first turning axis extending along a horizontal plane. The reading section reads an image on the sheet in a reading position in the conveying path. The first guide member is provided in the reading section. The second guide member is provided in a position opposed to the first guide member across the conveying path. A first end portion of the supporting section is supported to be rotatable around a second turning axis. The locking section is locked, from below, to a portion between the first end portion and a second end portion in the supporting section. The locking section rotates in a first direction from the first guide member toward the second guide member around the first turning axis.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] FIELD An embodiment of the present invention relates to an image reading device. [Background technology]

[0002] 2. Description of the Related Art Conventionally, an image reading device is used that reads an image on a sheet while conveying the sheet. Generally, a relatively thin sheet (plain paper) has a relatively low bending rigidity (relatively weak stiffness), and a relatively thick sheet (cardboard) has a relatively high bending rigidity (relatively strong stiffness). When an image on a sheet is read by an image reading device, the sheet may be bent along the conveying path along which the sheet is conveyed. In this case, the bending stress (bending moment) acting on the sheet changes depending on the thickness of the sheet. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-152463 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-137001 [Patent Document 3] Japanese Patent Application Publication No. 6-133121 Summary of the Invention [Problem to be solved by the invention]

[0004] SUMMARY OF THE INVENTION An object of the present invention is to provide an image reading apparatus capable of adjusting the bending stress acting on a sheet when reading an image on the sheet. [Means for solving the problem]

[0005] (1) An image reading device according to aspect 1 of this embodiment includes a frame, a conveying roller, a reading unit, a first guide member, a second guide member, a support member, and a locking member. The conveying roller conveys a sheet along a conveying path. The reading unit is rotatably supported by the frame around a first pivot axis that is aligned with a horizontal plane and is positioned above the conveying path. The reading unit reads an image of the sheet at a reading position downstream of a position on the conveying path corresponding to the conveying roller in a conveying direction in which the sheet is conveyed. The first guide member is provided on the conveying path side of the reading unit, straddling the reading position in the conveying direction, and contacts the sheet from above. The second guide member is provided at a position opposite the first guide member across the conveying path, straddling the reading position in the conveying direction, and contacts the sheet from below. The second guide member, together with the first guide member, holds the sheet so that it is convex from itself toward the first guide member in the conveying direction, centered on the reading position. The support portion has a first end supported by the frame so as to be rotatable about a second rotation axis along a horizontal plane, and a second end contacts the sheet from above on the downstream side of the reading position. A locking portion is provided on at least one of the reading portion and the first guide member, and locks onto a portion of the support portion between the first end and the second end from below. The locking portion rotates about the first rotation axis in a first direction, from the first guide member toward the second guide member, due to gravity acting on the reading portion, the first guide member, and itself.

[0006] (2) Aspect 2 of this embodiment may be the image reading device described in (1) above, which has a biasing member that biases the second end of the support portion from the first guide member toward the second guide member. (3) Aspect 3 of this embodiment may be an image reading device as described in (1) or (2), in which the second end of the support portion is positioned upstream of the first end of the support portion in the conveying direction.

[0007] (4) Aspect 4 of this embodiment may be an image reading device described in any one of (1) to (3) above, which has a pressure roller that is rotatably supported on the second end of the support portion and contacts the sheet from above downstream of the reading position. (5) Aspect 5 of this embodiment may be the image reading device described in (4) above, in which, when a line connecting the tip of the engaging portion protruding toward the conveying path and the tip of the second guide member protruding toward the conveying path downstream of the reading position is defined as a reference line, the pressure roller protrudes in the first direction around the first rotation axis beyond the reference line. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a side view showing an overview of an image reading apparatus according to an embodiment; [Figure 2] FIG. 2 is a side view of a main part of a transport / reading unit of the image reading apparatus according to the embodiment. [Figure 3] 1 is a perspective view of a main part of a transport / reading unit of an image reading apparatus according to an embodiment. [Figure 4] FIG. 3 is a view taken in the direction of the arrow A1 in FIG. 2. [Figure 5] FIG. 2 is a perspective view of the image reading device according to the embodiment, with a first guide member and other components cut away. [Figure 6] FIG. 2 is a side view of a main part of the image reading apparatus according to the embodiment when the image reading apparatus conveys cardboard. DETAILED DESCRIPTION OF THE INVENTION

[0009] An image reading apparatus according to an embodiment will be described below with reference to the drawings.

[0010] As shown in FIG. 1, the image reading device 1 of this embodiment has a transporting / reading unit 10 and a reading unit 55 . 1 and 2, the transport and reading unit 10 has an upper frame (frame) 11, a paper feed tray 12, a transport section 13, a back-side reading section (reading section) 14, a first guide member 15, a second guide member 16, a support section 17, a pressure roller 18, a locking section 19, a spring (urging member) 20, and a paper discharge tray 21. Note that FIG. 2 is a side view of the transport and reading unit 10 as viewed along a first rotation axis O1 and a second rotation axis O2, which will be described later. Hereinafter, the back-side reading section 14, the first guide member 15, and the locking section 19 will be referred to as a rotation unit 22. The upper frame 11 defines the outer shape of the main body of the transport / reading unit 10, excluding the paper feed tray 12 and the paper discharge tray 21. The upper frame 11 is a rectangular box. Openings (not shown) are formed in the portions of the upper frame 11 where the paper feed tray 12 and the paper discharge tray 21 are fixed.

[0011] 2 and 3, for example, the upper frame 11 has a first frame 24, a second frame 25, and a pair of third frames 26. In Fig. 3, the pair of third frames 26 are indicated by two-dot chain lines. The first frame 24 and the second frame 25 are formed by bending a steel plate, etc. The pair of third frames 26 are arranged to sandwich a transport path R1, which will be described later.

[0012] As shown in FIG. 1, the paper feed tray 12 is fixed to the side of the upper frame 11 at the middle in the vertical direction. As shown in FIGS. 2 and 3, the conveying section 13 has a pair of first conveying rollers (conveying rollers) 28 and a pair of second conveying rollers 29. The paper feed tray 12, the pair of first transport rollers 28, the pair of second transport rollers 29, and the paper discharge tray 21 form a transport path R1 along which the sheet P1 is transported (see also FIG. 1). As shown in Fig. 2, the pair of first conveyor rollers 28 are cylindrical and arranged to face each other. In this specification, "facing" also means "contacting." For example, the pair of first conveyor rollers 28 are supported rotatably around a rotation shaft 28a (see also Fig. 3) provided on the pair of third frames 26 of the upper frame 11.

[0013] The pair of second conveyor rollers 29 are each cylindrical and arranged to face each other. For example, the pair of second conveyor rollers 29 are supported rotatably around a rotation shaft 29a (see also FIG. 3) provided on a pair of third frames 26 of the upper frame 11. The rotation shaft 29a and the rotation shaft 28a are parallel to each other and extend along a horizontal plane. The pair of first conveying rollers 28 and the pair of second conveying rollers 29 convey the sheet P1 along the conveying path R1. The pair of second conveying rollers 29 are arranged downstream of the pair of first conveying rollers 28 in the conveying direction in which the sheet P1 is conveyed (hereinafter, simply referred to as the downstream side).

[0014] 2, the back side reading unit 14 is disposed above the conveying path R1. For example, the back side reading unit 14 has a housing 32, a lens unit 33, and an image sensor 34. For example, the housing 32 is shaped like a rectangular parallelepiped box. For example, in a natural state where no external force is acting on the rotating unit 22, the bottom surface 32a of the housing 32 is inclined gradually upward toward the downstream side. The housing 32 is supported rotatably about a first rotation axis O1 along a horizontal plane relative to the first frame 24 of the upper frame 11. It is preferable that a rotation restricting portion be provided on the upper frame 11 to restrict the range of rotation of the housing 32 about the first rotation axis O1 in a first direction D1 from the first guide member 15 toward the second guide member 16. In this case, when the turning unit 22 is in its natural state, the housing 32 is engaged with the rotation restricting portion from above the rotation restricting portion. Hereinafter, the direction opposite to the first direction D1 around the first rotation axis O1 will be referred to as a second direction D2.

[0015] The lens unit 33 and the image sensor 34 are built into the housing 32. The lens unit 33 has a plurality of lenses (not shown). The lens unit 33 is fixed to the lower surface 32a of the housing 32. The lens unit 33 forms an image of the second surface (rear surface) P3 of the sheet P1 on the light receiving surface 34a of the image sensor 34. The image sensor 34 acquires image data of the image formed on the light receiving surface 34a. As described above, the back surface reading unit 14 reads the image of the second surface P3 of the sheet P1 at the reading position P6, which is downstream of the position on the conveying path R1 corresponding to the pair of first conveying rollers 28. The reading position P6 refers to the position on the conveying path R1 where the back surface reading unit 14 reads the image of the second surface P3 of the sheet P1.

[0016] The first guide member 15 is a so-called back guide. As shown in FIG. 2, the first guide member 15 is fixed to the bottom surface 32a of the housing 32 of the back surface reading unit 14. The first guide member 15 is provided on the conveying path R1 side of the back surface reading unit 14 (between the back surface reading unit 14 and the conveying path R1) so as to straddle the reading position P6 in the conveying direction. The first guide member 15 is disposed above the conveying path R1. The first guide member 15 comes into contact with the sheet P1 from above the sheet P1. As shown in FIGS. 2 and 3, the first guide member 15 has a first inclined portion 37, a flat portion 38, and a plurality of second inclined portions 39.

[0017] 2, the first inclined portion 37 is fixed to an upstream portion of the lower surface 32a of the housing 32, opposite the downstream side in the conveying direction. The lower surface 37a of the first inclined portion 37 is inclined so as to gradually approach the lower surface 32a of the housing 32 as it moves downstream. The flat portion 38 is fixed to a middle portion in the conveying direction of the lower surface 32a of the housing 32. The lower surface 38a of the flat portion 38 is aligned with the lower surface 32a of the housing 32. A contact glass 38b is built into the flat portion 38 on the lower surface 38a side. The contact glass 38b is arranged so that the image sensor 34 forms an image of the second surface P3 of the sheet P1 on the light receiving surface 34a. The contact glass 38b is a member that transmits the image of the second surface P3 and also guides this image.

[0018] Here, a straight line passing through the lower surface 38a is defined as a first reference line L1. The upstream end of the lower surface 38a is continuous with the downstream end of the lower surface 37a of the first inclined portion 37. 4, the first inclined portion 37 and the flat portion 38 each extend over the entire width of the sheet P1. Note that the back side reading unit 14 and the second frame 25 are not shown in FIG. For example, sheet P1 is a sheet of A4 size according to the Japanese Industrial Standards.

[0019] 2, the second inclined portion 39 is fixed to a downstream portion of the lower surface 32a of the housing 32. The lower surface 39a at the downstream end of the second inclined portion 39 is inclined so as to gradually approach the lower surface 32a of the housing 32 as it moves downstream. The lower surface 39b of the second inclined portion 39 other than the lower surface 39a is inclined so as to gradually move away from the lower surface 32a of the housing 32 as it moves downstream. The downstream end of the lower surface 39b is continuous with the upstream end of the lower surface 39a. As shown in FIG. 3, the second inclined portions 39 are arranged at intervals in the width direction. As shown in FIG. 2, the lower surfaces 37a, 38a, 39b of the first guide member 15 are arranged so as to be convex from the second guide member 16 toward the first guide member 15, with the reading position P6 as the center in the conveying direction.

[0020] The first inclined portion 37, the flat portion 38 (excluding the contact glass 38b), and the plurality of second inclined portions 39 that constitute the first guide member 15 are made of synthetic resin, metal, or the like.

[0021] The second guide member 16 is provided opposite the first guide member 15 across the conveying path R1, straddling the reading position P6 in the conveying direction. The second guide member 16 has a first inclined piece 42 and a second inclined piece 43. The first inclined piece 42 and the second inclined piece 43 are arranged to sandwich the reading position P6 in the conveying direction. Specifically, the first inclined piece 42 is arranged upstream of the reading position P6. The second inclined piece 43 is arranged downstream of the reading position P6. The first inclined piece 42 is a so-called upstream guide. The first inclined piece 42 faces the first inclined portion 37 of the first guide member 15 and extends further upstream than the first inclined portion 37. An upper surface 42a at the downstream end of the first inclined piece 42 is substantially parallel to the lower surface 38a of the flat portion 38. An upper surface 42b of the first inclined piece 42 other than the upper surface 42a is inclined so as to gradually approach the first reference line L1 toward the downstream side. The downstream end of the upper surface 42b is continuous with the upstream end of the upper surface 42a. The connection between the upper surface 42a and the upper surface 42b faces the connection between the lower surface 37a and the lower surface 38a.

[0022] The second inclined piece 43 is a so-called downstream guide. The second inclined piece 43 faces the second inclined portion 39 of the first guide member 15 and extends downstream of the second inclined portion 39. An upper surface 43a at the upstream end of the second inclined piece 43 is inclined so as to gradually approach the first reference line L1 toward the downstream side. An upper surface 43b of the second inclined piece 43 other than the upper surface 43a is inclined so as to gradually move away from the first reference line L1 toward the downstream side. A connection portion 43c between the upper surface 43a and the upper surface 43b is a tip end of the second guide member 16 that projects toward the conveying path R1 (sheet P1) downstream of the reading position P6.

[0023] The first inclined piece 42 and the second inclined piece 43 are made of synthetic resin, metal, or the like. As described above, the first inclined piece 42 and the second inclined piece 43 of the second guide member 16 come into contact with the sheet P1 from below the sheet P1. The second guide member 16, together with the first guide member 15, holds the sheet P1 so that it is convex from the second guide member 16 toward the first guide member 15 in the conveyance direction, with the reading position P6 as the center.

[0024] For example, the support portion 17 has a first piece 46 and a second piece 47. The first piece 46 and the second piece 47 each extend in a predetermined direction. For example, a first end of the first piece 46 (a first end of the support portion 17) is supported by the first frame 24 of the upper frame 11 so as to be rotatable around a second rotation axis O2. The second rotation axis O2 is an axis that is along the horizontal plane and is parallel to the first rotation axis O1 and the rotation axis 29a. The second rotation axis O2 is located downstream of the reading position P6. The first end of the first piece 46 may be directly supported by the upper frame 11 so as to be rotatable relative to the upper frame 11. The first end of the first piece 46 may share a rotation axis with the rotation axis 29a.

[0025] A first end of the second piece 47 is connected to a second end of the first piece 46 on the opposite side to the first end. Hereinafter, the portion where the first piece 46 and the second piece 47 are connected will be referred to as a connection portion 17a. A second end of the second piece 47 on the opposite side to the first end (a second end of the support portion 17) is located upstream of the first end of the first piece 46. Note that the second end of the second piece 47 may also be located downstream of the first end of the first piece 46. The first piece 46 and the second piece 47 are V-shaped and convex obliquely downward in the side view shown in FIG. The pressure roller 18 is cylindrical and disposed along a horizontal plane. The pressure roller 18 is rotatably supported on the second end of the second piece 47. The pressure roller 18 is disposed downstream of the connecting portion 43c of the second inclined piece 43. The pressure roller 18 comes into contact with the sheet P1 downstream of the reading position P6 from above the sheet P1. The second end of the second piece 47 comes into contact with the sheet P1 downstream of the reading position P6 from above the sheet P1 via the pressure roller 18. The support portion 17 and the pressure roller 18 are disposed downstream of the reading position P6.

[0026] 2 and 5, the locking portion 19 is rod-shaped and extends along the first rotation axis O1. As shown in Fig. 5, the locking portion 19 is provided at the lower end of the second inclined portion 39 of the first guide member 15. As shown in Fig. 2, the locking portion 19 locks onto the connection portion 17a of the support portion 17 from below the connection portion 17a. The portion of the support portion 17 that is engaged with the engaging portion 19 is not limited as long as it is a portion between the first end of the first piece 46 and the second end of the second piece 47. When the housing 32 is not locked by the rotation restricting portion, gravity acting on the rotation unit 22 causes the rotation unit 22 to rotate about the first rotation axis O1 in the first direction D1.

[0027] The locking portion 19 may be provided on the back surface reading unit 14, or may be provided on both the back surface reading unit 14 and the first guide member 15. 2, a line connecting the tip 19a of the locking portion 19 protruding toward the conveying path R1 (sheet P1) and the connecting portion 43c of the second inclined piece 43 is defined as a second reference line (reference line) L2. It is preferable that the pressure roller 18 protrudes further than the second reference line L2 in the first direction D1 around the first rotation axis O1 (from the first guide member 15 toward the second guide member 16).

[0028] For example, the spring 20 is a helical spring and is used as a compression spring. As shown in FIG. 3, the spring 20 is disposed between the second inclined portions 39 of the first guide member 15 that are adjacent to each other in the width direction. A first end of the spring 20 is fixed to the lower surface of the second frame 25 of the upper frame 11. Alternatively, the first end of the spring 20 may be fixed to the first guide member 15. As shown in FIG. 5, a second end of the spring 20 opposite to the first end is in contact with the second piece 47 of the support portion 17 from above the second piece 47. The spring 20 biases the second end of the second piece 47 from the first guide member 15 toward the second guide member 16 . 1, the paper discharge tray 21 is fixed to the lower end of the side surface of the upper frame 11. The paper discharge tray 21 is disposed lower than the paper feed tray 12.

[0029] There are no limitations on the configuration of the reading unit 55. The reading unit 55 is disposed below the transport and reading unit 10 and is fixed to the upper frame 11 of the transport and reading unit 10. For example, the reading unit 55 has a lower frame 56, a contact glass 57, and a surface reading unit 58. The lower frame 56 defines the outer shape of the reading unit 55. The lower frame 56 is in the shape of a rectangular parallelepiped box that is open at the top. The contact glass 57 is flat and fixed to the opening of the lower frame 56. The transport path R1 passes over the contact glass 57. The front surface reading unit 58 is configured in the same manner as the back surface reading unit 14. The front surface reading unit 58 reads an image of the first surface (front surface) P2 of the sheet P1, which is opposite to the second surface P3. The front surface reading unit 58 is built into the lower frame 56. The front surface reading unit 58 may be movable along the contact glass 57 within the lower frame 56.

[0030] Next, the operation of the image reading device 1 configured as above will be described. First, the case where the sheet P1 is a relatively thin plain paper P11 will be described. For example, the plain paper P11 is paper with a thickness of less than 0.21 mm. The user places a plurality of sheets of plain paper P11 on the paper feed tray 12 of the image reading device 1. The plurality of sheets of plain paper P11 are stacked one on top of the other in the thickness direction of the sheets of plain paper P11. When a user starts the image reading device 1, the conveying / reading unit 10 conveys the plain paper sheets P11 downstream by the conveying section 13 in order from the uppermost plain paper sheet P11 among the plurality of plain paper sheets P11. When plain paper P11 being transported along transport path R1 passes over the reading unit 55, the front side reading section 58 reads the image of the first side P2 of the plain paper P11. The plain paper P11 being transported downstream by the pair of first transport rollers 28 passes between the first guide member 15 and the second guide member 16 along transport path R1. The first guide member 15 and the second guide member 16 hold the plain paper P11 so that it forms a convex shape centered on the reading position P6 in the transport direction, from the second guide member 16 toward the first guide member 15.

[0031] Because plain paper P11 has a relatively low bending rigidity, the plain paper P11 cannot rotate the rotating unit 22 about the first rotation axis O1 in the second direction D2, resisting the force that rotates the rotating unit 22 about the first rotation axis O1 in the first direction D1, upstream of the reading position P6. The radius of curvature that the plain paper P11 can be bent becomes relatively small, and a certain bending stress acts on the plain paper P11. Downstream of the reading position P6, the plain paper P11 is sandwiched between the pressure roller 18 and the second guide member 16, and is transported downstream in a stable state. The back-side reading unit 14 reads an image of the second side P3 of the plain paper P11 through the contact glass 38b of the flat portion 38 when the plain paper P11 passes through the reading position P6. The plain paper P11, from which the image on the second side P3 has been read, is transported downstream by a pair of second transport rollers 29. The plain paper P11, from which the images on the first side P2 and second side P3 have been read, is discharged onto the paper output tray 21. The images read by the front side reading unit 58 and the back side reading unit 14 are converted as appropriate and stored within the image reading device 1.

[0032] On the other hand, when the sheet P1 is thick paper P13 as shown in Fig. 6, the bending rigidity of the thick paper P13 is relatively large. For example, the thick paper P13 is paper having a thickness of 0.21 mm or more. Therefore, the restoring force of the cardboard P13 causes the rotating unit 22 to rotate in the second direction D2 around the first rotation axis O1, resisting the force that rotates the rotating unit 22 in the first direction D1 around the first rotation axis O1. The radius of curvature around which the cardboard P13 is bent becomes relatively large, and the bending stress acting on the cardboard P13 becomes small. Note that in Figure 6, the shape of the first guide member 15 before it rotates in the second direction D2 is shown by a two-dot chain line. When the support part 17, which is locked from below by the locking part 19, rotates around the second rotation axis O2, the pressure roller 18 moves away from the second inclined piece 43 of the second guide member 16, suppressing an increase in the transport resistance of the cardboard P13 and the occurrence of jitter (a phenomenon in which the read color differs from the actual color of the image) when the leading edge of the cardboard P13 enters between the pressure roller 18 and the second guide member 16. When the cardboard P13 passes between the first guide member 15 and the second guide member 16, gravity acting on the rotating unit 22 causes the rotating unit 22 to rotate around the first rotation axis O1 in the first direction D1 and engage with the rotation restricting portion. As described above, the image reading device 1 of this embodiment can adjust the bending stress acting on the sheet P1 when reading the image on the sheet P1.

[0033] The image reading device 1 has a spring 20. The spring 20 presses the sheet P1 via the support portion 17, so the pressure roller 18 can be returned to a predetermined position where it contacts the sheet P1. A bending stress can be applied to the sheet P1 during transport. Also, loosening and fluttering of the plain paper P11 at the reading position P6 can be suppressed. The second end of the support portion 17 is positioned upstream of the first end of the support portion 17. This makes it less likely that the first end of the support portion 17 will interfere with the reading position P6. Furthermore, the plain paper P11 is alternately sandwiched between the pressure roller 18 and the second inclined pieces 43 of the second guide member 16, causing the plain paper P11 to bend even more. This stabilizes the transport of the plain paper P11. To stabilize the transport of the plain paper P11, the position where the plain paper P11 is sandwiched needs to be somewhat close to the reading position P6. In that case, interference with the back-side reading unit 14 and the reading position P6 becomes unavoidable in order to create space for the second rotation shaft O2 and the first end of the support portion 17. Furthermore, by adopting the configuration of this embodiment, it is possible to effectively use (increase) the displacement of the locking portion 19 required for the pressure roller 18 to separate from the second guide member 16 and escape to the outside of the transport path R1.

[0034] The image reading device 1 has a pressure roller 18. This can reduce the influence on the sheet P1 when the support portion 17 comes into contact with the sheet P1. The pressure roller 18 may protrude beyond the second reference line L2 in the first direction D1 around the first rotation axis O1. In this case, stiffness is generated in the sheet P1, and the sheet P1 can be brought into contact with the back-side reading unit 14 more reliably.

[0035] It should be noted that the biasing member is the spring 20. However, the biasing member is not limited to the spring 20, and may be synthetic rubber or the like. The number of first conveying rollers 28 included in the conveying / reading unit 10 may be one. The conveying / reading unit 10 may not have the paper feed tray 12, the pressure roller 18, the paper discharge tray 21, the spring 20, or the pair of second conveying rollers 29. If the conveying / reading unit 10 does not have the pressure roller 18, the second end of the support portion 17 comes into direct contact with the sheet P1. The image reading device 1 does not necessarily have to have the reading unit 55 .

[0036] According to at least one of the embodiments described above, the support portion 17, the locking portion 19, and the rotation axes O1 and O2 make it possible to adjust the bending stress acting on the seat P1.

[0037] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention described in the claims and their equivalents. [Explanation of symbols]

[0038] 1...image reading device, 11...upper frame (frame), 14...rear surface reading section (reading section), 15...first guide member, 16...second guide member, 17...support section, 18...pressure roller, 19...locking section, 20...spring (urging member), 28...first conveying roller (conveying roller), D1...first direction, L2...second reference line (reference line), O1...first rotating shaft, O2...second rotating shaft, P1...sheet, P6...reading position, R1...conveying path

Claims

1. The frame and a conveying roller for conveying the sheet along a conveying path; a reading unit that is rotatably supported by the frame around a first rotation axis along a horizontal plane, is disposed above the conveying path, and reads an image of the sheet at a reading position downstream of a position corresponding to the conveying roller on the conveying path in a conveying direction in which the sheet is conveyed; a first guide member that is provided on the reading unit on the conveyance path side of the reading unit so as to straddle the reading position in the conveyance direction, and that comes into contact with the sheet from above the sheet; a second guide member that is provided at a position facing the first guide member across the conveyance path so as to straddle the reading position in the conveyance direction, contacts the sheet from below, and, together with the first guide member, holds the sheet so that the sheet is convex from itself toward the first guide member in the conveyance direction, centered on the reading position; a support portion having a first end portion supported so as to be rotatable about a second rotation axis along a horizontal plane relative to the frame, and a second end portion contacting from above the sheet downstream of the reading position; a locking portion provided on at least one of the reading unit and the first guide member, the locking portion locking from below to a portion of the support portion between the first end and the second end, and rotating around the first pivot axis in a first direction from the first guide member toward the second guide member due to gravity acting on the reading unit, the first guide member, and the locking portion itself; An image reading device comprising:

2. 2. The image reading device according to claim 1, further comprising a biasing member that biases the second end of the support portion from the first guide member toward the second guide member.

3. The image reading device according to claim 1 , wherein the second end of the support portion is disposed upstream of the first end of the support portion in the transport direction.

4. The image reading device according to claim 1 , further comprising a pressure roller rotatably supported on the second end of the support portion and contacting the sheet from above on the downstream side of the reading position.

5. When a line connecting the leading end of the locking portion protruding toward the conveying path and the leading end of the second guide member protruding toward the conveying path on the downstream side of the reading position is defined as a reference line, 5. The image reading device according to claim 4, wherein the pressure roller protrudes in the first direction around the first rotation axis beyond the reference line.

Images