Medium transport device, image reading device and printing device

Abstract

To provide a medium transport device, an image reading device, and a printing device that can reduce design constraints.SOLUTION: This device comprises a rotating body 30 that rotates in contact with a medium, a conductive rotating shaft 31 to which the rotating body 30 is attached and which rotates the rotating body 30, a bearing 40 that rotatably holds the rotating shaft 31, a conductive abutment portion 42 that is provided between the rotating body 30 and the bearing 40 in the axial direction of the rotating shaft 31 and that can abut against the rotating shaft 31, and a grounding member 53 that grounds the abutment portion 42.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a medium transport device, an image reading device, and a printing device. [Background technology]

[0002] For example, Patent Document 1 discloses an automatic paper feeder, which is an example of a medium transport device. The automatic paper feeder includes a rotating roller, which is an example of a rotating body, and a metal rotating shaft, which is an example of a rotating shaft. The metal rotating shaft is the axis of the rotating roller. The rotating roller transports, for example, a document, which is an example of a medium. When the rotating roller rotates, static electricity may be generated due to friction. Therefore, the automatic paper feeder grounds the metal rotating shaft via a conductive bearing, a metal elastic material, and a metal side panel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-178518 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, a metallic elastic material is sandwiched between a conductive bearing and a metallic side plate. The conductive bearing ensures electrical continuity by bringing the metallic elastic material into surface contact with the metallic side plate. This may result in design restrictions. [Means for solving the problem]

[0005] A medium transport device that solves the above problem comprises a rotating body that rotates in contact with the medium, a conductive rotating shaft to which the rotating body is attached and which rotates the rotating body, a bearing that rotatably holds the rotating shaft, a conductive abutment portion that is provided between the rotating body and the bearing in the axial direction of the rotating shaft and can abut against the rotating shaft, and a grounding member that grounds the abutment portion.

[0006] An image reading device that solves the above problem comprises a medium conveying device that includes a rotating body that rotates in contact with a medium, a conductive rotating shaft to which the rotating body is attached and which rotates the rotating body, a bearing that rotatably holds the rotating shaft, a conductive abutment portion that is provided between the rotating body and the bearing in the axial direction of the rotating shaft and can abut against the rotating shaft, and a grounding member that grounds the abutment portion, and a reading unit that reads an image on a medium conveyed by the medium conveying device.

[0007] A printing device that solves the above problem includes an image reading device having the above configuration, and a printing unit that prints an image read by the image reading device. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram of an embodiment of a printing device. [Figure 2] FIG. 2 is a schematic side view of the medium transport device in which the path formation unit is located at the closed position. [Figure 3] FIG. 3 is a schematic side view of the medium transport device in which the path formation unit is located in the open position. [Figure 4] FIG. 4 is a schematic plan view of the medium transport device. [Figure 5] FIG. 5 is a perspective view of the medium transport device. [Figure 6] FIG. 6 is a cross-sectional view taken along line 6-6 in FIG. [Figure 7] 7 is a cross-sectional view taken along line 7-7 in FIG. [Figure 8] FIG. 8 is a schematic diagram of a modified example of the grounding member. DETAILED DESCRIPTION OF THE INVENTION

[0009] [Embodiment] Hereinafter, an embodiment of a medium transport device, an image reading device, and a printing device will be described with reference to the drawings. The image reading device is, for example, a sheet-fed scanner that reads images on a transported medium such as paper or film using a fixed reading unit. The printing device is, for example, an inkjet printer that prints by ejecting ink, which is an example of a liquid, onto a medium such as paper, fabric, vinyl, plastic parts, or metal parts.

[0010] In the drawings, the printing device 11 is assumed to be placed on a horizontal plane, with the direction of gravity indicated by the Z axis and directions along the horizontal plane indicated by the X and Y axes. The X, Y, and Z axes are perpendicular to one another. In the following description, the direction parallel to the X axis is also referred to as the width direction X.

[0011] <Printing device> As shown in FIG. 1, the printing device 11 includes a printing unit 12 and an image reading device 13. The printing unit 12 is capable of printing an image read by the image reading device 13. The printing unit 12 may print on the medium 15 by ejecting a liquid from one or more nozzles (not shown).

[0012] <Image reader> 2, image reading device 13 reads an image on medium 15. Medium 15 read by image reading device 13 may be medium 15 printed by printing unit 12, or may be a manuscript, a photograph, or the like.

[0013] The image reading device 13 may include a feed tray 17. The medium 15 before being read can be set on the feed tray 17. A plurality of sheets of the medium 15 can be placed on the feed tray 17 in a stacked state.

[0014] The image reading device 13 may include a discharge tray 18. The discharge tray 18 receives the medium 15 after reading. A plurality of sheets of the medium 15 can be stacked on the discharge tray 18.

[0015] The image reading device 13 includes a reading unit 20 and a medium conveying device 21. The image reading device 13 may include multiple reading units 20. The reading unit 20 is capable of reading an image on the medium 15 conveyed by the medium conveying device 21. The reading unit 20 is provided along a conveying path 23 of the medium 15. In the drawings, the conveying path 23 is indicated by a dashed line. The multiple reading units 20 may each read an image on a different side of the medium 15. For example, one reading unit 20 is capable of reading an image on the front side of the medium 15. The other reading unit 20 is capable of reading an image on the back side of the medium 15. The reading unit 20 may include, for example, a contact optical sensor. The reading unit 20 may include, for example, a reduction optical sensor.

[0016] <Media transport device> The medium transport device 21 transports the medium 15 in the transport direction D along the transport path 23. The transport path 23 is, for example, a path connecting the feed tray 17 and the discharge tray 18. The medium transport device 21 sends the medium 15 set in the feed tray 17 to the discharge tray 18. The medium transport device 21 may separate the multiple media 15 set in the feed tray 17 one by one and transport them in order. The medium transport device 21 may also discharge the transported media 15 to the discharge tray 18.

[0017] The medium conveying device 21 may include a path forming unit 24. The path forming unit 24 is non-conductive. The path forming unit 24 forms a conveying path 23 along which the medium 15 is conveyed. The path forming unit 24 has a path surface 24a and a back surface 24b. The path surface 24a forms the conveying path 23. The path surface 24a is the surface that comes into contact with the medium 15 being conveyed along the conveying path 23 or that faces the medium 15. The back surface 24b is the surface opposite to the path surface 24a. In this embodiment, the back surface 24b is the upper surface.

[0018] 2 and 3, the path forming unit 24 is movable between a closed position shown in Fig. 2 and an open position shown in Fig. 3. The path forming unit 24 positioned at the closed position forms the conveying path 23. The path forming unit 24 positioned at the open position exposes the path surface 24a.

[0019] The medium transport device 21 may include a feed unit 26. The feed unit 26 sends, for example, the uppermost medium 15 out of the media 15 set in the feed tray 17 to the transport path 23. The feed unit 26 may include a feed shaft 27, a feed roller 28, a frame 29, a rotating body 30, a rotating shaft 31, a drive gear 32, and a retard roller 33.

[0020] The feed shaft 27 may rotatably support the feed roller 28. The feed shaft 27 may rotate the feed roller 28. The feed shaft 27 is supported by a frame 29. The feed shaft 27 extends in the width direction X. The feed shaft 27 is provided parallel to the rotation shaft 31.

[0021] The feed roller 28 is supported by the frame body 29 via a feed shaft 27. The feed roller 28 rotates around the feed shaft 27. The feed roller 28 may be provided at the center of the conveyance path 23 in the width direction X.

[0022] The frame 29 is rotatable about a rotation axis 31. The frame 29 reciprocates the feed roller 28 between a separated position shown by a solid line in Fig. 2 and a feed position shown by a two-dot chain line in Fig. 2. The separated position is a position where the feed roller 28 is separated from the medium 15 set in the feed tray 17 .

[0023] The feeding position is a position where the feeding roller 28 comes into contact with the medium 15 set in the feeding tray 17. When the feeding roller 28 moves from the separated position to the feeding position, it comes into contact with the medium 15 set in the feeding tray 17 from above. If there is no medium 15 set in the feeding tray 17, the feeding roller 28 may come into contact with the feeding tray 17. The feeding roller 28 rotates in the feeding position to send the medium 15 from the feeding tray 17 to the transport path 23.

[0024] The rotating shaft 31 is conductive. The rotating shaft 31 extends in the width direction X. That is, the axial direction of the rotating shaft 31 is the width direction X. A rotating body 30 is attached to the rotating shaft 31. A drive gear 32 is attached to the rotating shaft 31. In the axial direction of the rotating shaft 31, the rotating body 30 and the drive gear 32 may be located at both ends of the rotating shaft 31. The rotating body 30 may be located at a first end 31f shown in FIG. 4. The drive gear 32 may be located at a second end 31s shown in FIG. 4. When a driving force is input to the drive gear 32, the rotating shaft 31 rotates together with the drive gear 32. The rotating shaft 31 rotates the rotating body 30.

[0025] The rotating body 30 is located downstream of the feed roller 28 in the conveying direction D. The rotating body 30 sandwiches the medium 15 fed by the feed roller 28 between itself and the retard roller 33. The rotating body 30 rotates in a direction that feeds the medium 15 in the conveying direction D. Specifically, the rotating body 30 rotates clockwise in FIG. 2. The rotating body 30 rotates in contact with the medium 15.

[0026] The rotating body 30 and the retard roller 33 are configured to separate the media 15 one by one. That is, the rotating body 30 of this embodiment is a separation roller that separates a plurality of overlapping media 15.

[0027] The retard roller 33 may be rotatable in a forward direction and a reverse direction. The forward direction is the direction that returns the medium 15 to the feed tray 17. The forward direction is the clockwise direction in FIG. 2. A driving source (not shown) rotates the retard roller 33 in the forward direction. The reverse direction is the direction opposite to the forward direction.

[0028] When multiple sheets of media 15 are sandwiched between the rotating body 30 and the retard roller 33, the first sheet of media 15 located on top is sent in the conveying direction D by the rotating body 30. At this time, the second and subsequent sheets of media 15 are returned in the direction opposite to the conveying direction D by the retard roller 33. Therefore, the feeding unit 26 can feed the media 15 one by one.

[0029] A torque limiter may be provided on the retard roller 33. The torque limiter may block the transmission of the driving force when the retard roller 33 receives a predetermined force in the reverse direction. For example, when one sheet of medium 15 is sandwiched between the rotating body 30 and the retard roller 33, the medium 15 is transported in the transport direction D by the rotating body 30. The retard roller 33 comes into contact with the medium 15 being transported in the transport direction D. In other words, the retard roller 33 receives a force in the reverse direction from the medium 15. Therefore, the transmission of the driving force to the retard roller 33 is blocked by the torque limiter. The retard roller 33 may rotate in response to the medium 15 being transported in the transport direction D.

[0030] The medium conveying device 21 may include a conveying unit 35. The conveying unit 35 conveys the medium 15 sent by the feeding unit 26 along the conveying path 23. The conveying unit 35 discharges the medium 15 to the discharge tray 18. The conveying unit 35 may have a conveying roller 36, a driven rotor 37, and a support shaft 38. The conveying unit 35 may have multiple conveying rollers 36, multiple driven rotors 37, and multiple support shafts 38.

[0031] The transport roller 36 transports the medium 15 by rotating with the medium 15 sandwiched between the transport roller 36 and the driven rotor 37. The driven rotor 37 rotates in response to the medium 15 being transported.

[0032] The support shaft 38 extends in the width direction X. One support shaft 38 may support a plurality of driven rotors 37 spaced apart in the width direction X. The support shaft 38 rotatably supports the driven rotors 37. The support shaft 38 is conductive. The support shaft 38 may be supported by the path forming portion 24. The support shaft 38 is located on the back surface 24b side of the path forming portion 24.

[0033] The rotating shaft 31 and the support shaft 38 may move together with the path forming unit 24. For example, if the medium 15 becomes clogged in the transport path 23, the user can easily remove the medium 15 by moving the path forming unit 24 to the open position shown in FIG. 3. The user may replace the rotating body 30 by positioning the path forming unit 24 in the open position. The user may remove the frame 29 and the rotating body 30 from the first end 31f side by moving them in the opposite direction to the drive gear 32. The user may replace the feed roller 28 or the rotating body 30.

[0034] As shown in Figures 4 and 5, the medium conveying device 21 includes a bearing 40. The medium conveying device 21 may include multiple bearings 40. The multiple bearings 40 are provided at intervals in the width direction X. The bearings 40 are located between the rotating body 30 and the drive gear 32. The bearings 40 may be provided in the path forming section 24. For example, the bearings 40 are provided on the back surface 24b of the path forming section 24. The bearings 40 rotatably hold the rotating shaft 31.

[0035] The medium conveying device 21 has an abutment portion 42. The abutment portion 42 is provided between the rotating body 30 and the bearing 40 in the axial direction of the rotating shaft 31. When the medium conveying device 21 has multiple bearings 40, the abutment portion 42 is located between the rotating body 30 and the bearing 40 located farthest from the rotating body 30. Therefore, it can be said that the rotating body 30 is attachable to and detachable from the rotating shaft 31 from the side opposite the abutment portion 42. The abutment portion 42 is conductive. The abutment portion 42 is able to abut against the rotating shaft 31.

[0036] 6, the contact portion 42 is provided on the opposite side of the path surface 24a with respect to the path forming portion 24. The contact portion 42 is provided on the back surface 24b side with respect to the path forming portion 24. The abutment portion 42 has a flange portion 43 and a ring portion 44. A hole 45 is formed in the abutment portion 42. The hole 45 penetrates the ring portion 44. That is, the hole 45 is formed in the ring portion 44. The hole 45 may be circular. The diameter of the hole 45 is larger than the diameter of the rotating shaft 31. The rotating shaft 31 can pass through the hole 45. Therefore, the hole 45 can be said to penetrate the rotating shaft 31 in the axial direction. The hole 45 has play relative to the rotating shaft 31. The rotating shaft 31 can rotate smoothly relative to the abutment portion 42. The abutment portion 42 may be made of a metal body or a sintered body. For example, if the abutment portion 42 uses a sintered oil-impregnated bearing, which is a sintered body impregnated with lubricating oil, friction between the rotating shaft 31 and the abutment portion 42 can be reduced. Furthermore, if the abutment portion 42 uses a sintered oil-impregnated bearing, friction between the abutment portion 42 and the ground contact member 53, which will be described later, can be reduced.

[0037] The flange portion 43 protrudes from the ring portion 44 in the radial direction of the hole 45. The diameter of the flange portion 43 is larger than the diameter of the ring portion 44. The flange portion 43 protrudes from the ring portion 44. The outer peripheral surface of the ring portion 44 may include a cylindrical surface 47 and a flat surface 48. The outer peripheral surface may include a plurality of cylindrical surfaces 47 and a plurality of flat surfaces 48. The two flat surfaces 48 included in this embodiment are parallel to each other. The cylindrical surface 47 is, for example, a curved surface including an arc that is concentric with the hole 45. The flat surface 48 is, for example, a flat surface including a chord that is concentric with the hole 45.

[0038] The path forming portion 24 may have a holding portion 50. The holding portion 50 holds the abutment portion 42. The holding portion 50 holds the flange portion 43. Therefore, the holding portion 50 limits movement of the abutment portion 42 in the axial direction of the rotation shaft 31. The holding portion 50 may have a stopper 51 that contacts the flat surface 48. The holding portion 50 may have the same number of stoppers 51 as the number of flat surfaces 48. The stopper 51 may limit displacement of the abutment portion 42 in a direction intersecting the flat surface 48, while allowing displacement of the abutment portion 42 parallel to the flat surface 48. In other words, the holding portion 50 may hold the abutment portion 42 so that it cannot rotate. The holding portion 50 may hold the abutment portion 42 so that it can be displaced in a direction along the flat surface 48. The holding portion 50 of this embodiment holds the abutment portion 42 so that it can be displaced in the vertical direction.

[0039] 4 and 5, the medium conveying device 21 includes a grounding member 53. The grounding member 53 grounds the contact portion 42. The grounding member 53 grounds the contact portion 42 when the path forming portion 24 is in the closed position. The grounding member 53 may include a fixed portion 54 and a movable portion 55.

[0040] The fixed portion 54 in this embodiment is made of sheet metal. The medium conveying device 21 may directly ground the fixed portion 54, or may have a grounded member electrically connected to the fixed portion 54. The grounded member may be provided in the image reading device 13 or in the printing device 11. The fixed portion 54 may be fixed to the main body of the medium conveying device 21. The fixed portion 54 is provided separately from the path forming portion 24. Even if the path forming portion 24 moves, the fixed portion 54 does not move.

[0041] The movable part 55 in this embodiment is made of wire. The movable part 55 may be elastic. That is, the grounding member 53 may be elastic. The movable part 55 may have a torsion spring part 55a and a cantilever spring part 55b. The movable part 55 is attached to the path forming part 24. The movable part 55 is movable together with the path forming part 24.

[0042] 7, the torsion spring portion 55a of the movable portion 55 may be in contact with the fixed portion 54. The torsion spring portion 55a is in contact with the fixed portion 54 when the path forming portion 24 is in the closed position. The torsion spring portion 55a is elastically deformed from the shape shown by the two-dot chain line to the shape shown by the solid line when the path forming portion 24 is in the closed position from the open position. By bringing the torsion spring portion 55a into contact with the fixed portion 54 in the elastically deformed state, stable electrical conduction between the movable portion 55 and the fixed portion 54 can be achieved.

[0043] As shown in FIGS. 4 and 5 , the end of the cantilever spring portion 55b opposite to the torsion spring portion 55a abuts against the abutting portion 42. The cantilever spring portion 55b may be placed on the flange portion 43. The cantilever spring portion 55b presses the flange portion 43 downward. That is, the grounding member 53 urges the abutting portion 42 downward. The grounding member 53 may urge the abutting portion 42 toward the rotation shaft 31.

[0044] The medium conveying device 21 may include a conductive member 57. The conductive member 57 is electrically conductive. The conductive member 57 electrically connects the support shaft 38 and the contact portion 42. The conductive member 57 may include a coil spring 58 and a wire 59.

[0045] The coil spring 58 abuts against the support shaft 38. The coil spring 58 may press the support shaft 38 to press the driven rotor 37 against the transport roller 36. The wire 59 may press the coil spring 58 from the side opposite the support shaft 38. The wire 59 abuts against the coil spring 58. That is, the support shaft 38, the coil spring 58, and the wire 59 are electrically connected to one another. The end of the wire 59 opposite the end abutting against the coil spring 58 may abut against the abutment portion 42. The wire 59 is placed on the flange portion 43. The wire 59 presses the flange portion 43 downward. The conductive member 57 may urge the abutment portion 42 in the same direction as the grounding member 53. The conductive member 57 may urge the abutment portion 42 toward the rotation shaft 31.

[0046] The direction in which the grounding member 53 and the conductive member 57 urge the contact portion 42 may coincide with the direction in which the holding portion 50 allows displacement of the contact portion 42. In other words, the holding portion 50 holds the contact portion 42 so that it can be displaced in the urging direction in which the grounding member 53 urges the contact portion 42.

[0047] The holding portion 50 may hold the grounding member 53. The holding portion 50 may hold the conductive member 57. The holding portion 50 may limit the movement of the grounding member 53 and the conductive member 57. The tip of the holding portion 50 may be located above the upper end of the flange portion 43. The tip of the holding portion 50 may be located above the positions where the grounding member 53 and the conductive member 57 each abut against the abutting portion 42. The holding portion 50 may extend beyond the grounding member 53 in a direction opposite to the direction in which the grounding member 53 urges the abutting portion 42. The grounding member 53 and the conductive member 57 may urge the abutting portion 42 downward at positions below the tip of the holding portion 50.

[0048] <Operation of this embodiment> The operation of this embodiment will be described. The rotating body 30 is grounded via the rotating shaft 31, the contact portion 42, and the grounding member 53. The rotating body 30 is rotatable in a state where it is difficult to become charged.

[0049] <Effects of this embodiment> The effects of this embodiment will be described. (1-1) The contact portion 42 can contact the rotating shaft 31. Contact refers to a state in which one contacts the other to allow electrical continuity. In other words, the contact portion 42 is electrically connected to the rotating shaft 31 by contacting the rotating shaft 31. The grounding member 53 grounds the contact portion 42. By grounding the rotating shaft 31 using the contact portion 42 separate from the bearing 40, design constraints can be reduced.

[0050] (1-2) For example, if the contact portion 42 is misaligned with respect to the rotary shaft 31, there is a risk that the contact between the contact portion 42 and the rotary shaft 31 may be released. To address this issue, the contact portion 42 is formed with a hole 45 having a diameter larger than the diameter of the rotary shaft 31. That is, the rotary shaft 31 can be inserted into the hole 45 of the contact portion 42. Therefore, the contact portion 42 and the rotary shaft 31 can be brought into stable contact with each other.

[0051] (1-3) The contact portion 42 is provided on the opposite side of the path surface 24a with respect to the path forming portion 24. By effectively utilizing the space created by providing the path forming portion 24, it is possible to prevent the device from becoming large.

[0052] (1-4) The bearing 40 is provided on the back surface 24b of the path forming portion 24. The back surface 24b is the surface opposite to the path surface 24a. By effectively utilizing the space created by providing the path forming portion 24, it is possible to prevent the device from becoming large.

[0053] (1-5) The abutment portion 42 has a ring portion 44 and a flange portion 43. The diameter of a hole 45 formed in the ring portion 44 is larger than the diameter of the rotating shaft 31. Therefore, the abutment portion 42 is movable in the axial direction relative to the rotating shaft 31 inserted in the hole 45. In this regard, the path forming portion 24 has a holding portion 50. The holding portion 50 holds the flange portion 43. Therefore, the axial movement of the abutment portion 42 can be restricted.

[0054] (1-6) For example, when the contact portion 42 rotates, there is a risk of abnormal noise being generated. In this regard, the holding portion 50 holds the contact portion 42 so that it cannot rotate. Therefore, the generation of abnormal noise due to the rotation of the contact portion 42 can be suppressed.

[0055] (1-7) For example, when the stopper 51 is brought into contact with the cylindrical surface 47 to disable rotation of the contact portion 42 by friction, it is necessary to press the stopper 51 against the cylindrical surface 47 with a large force. In this case, the stopper 51 contacts the flat surface 48. Therefore, it is possible to easily disable rotation of the contact portion 42.

[0056] (1-8) The ground contact member 53 biases the displaceable contact portion 42 toward the rotation shaft 31. This allows the ground contact member 53 and the contact portion 42, and the contact portion 42 and the rotation shaft 31 to be stably contacted to each other.

[0057] (1-9) The holding portion 50 extends in the direction opposite to the biasing direction beyond the ground contact member 53. This reduces the risk that the abutting portion 42, which is biased in the biasing direction by the ground contact member 53, will come off the holding portion 50.

[0058] (1-10) The path forming unit 24 is movable. The bearing 40 is provided in the path forming unit 24. Therefore, the rotating shaft 31 held by the bearing 40 moves together with the path forming unit 24. The structure for grounding the moving rotating shaft 31 cannot be fixed. The grounding member 53 grounds the contact portion 42 when the path forming unit 24 forms the transport path 23. Therefore, the influence of the electrically charged rotating body 30 on the medium 15 on the transport path 23 can be reduced.

[0059] (1-11) The grounding member 53 biases the contact portion 42 toward the rotating shaft 31. That is, the grounding member 53 presses the contact portion 42 against the rotating shaft 31. Therefore, the grounding member 53, the contact portion 42, and the rotating shaft 31 can be stably contacted with each other.

[0060] (1-12) For example, if the separation roller deteriorates, there is a risk that the media 15 may be transported while overlapping. In this regard, the rotating body 30, which is the separation roller, can be attached and detached from the side opposite the contact portion 42. Therefore, the rotating body 30 can be easily replaced while the contact portion 42 remains in contact with the rotation shaft 31.

[0061] (1-13) The conductive member 57 electrically connects the support shaft 38 and the contact portion 42. That is, the driven rotor 37 is grounded via the support shaft 38, the conductive member 57, the contact portion 42, and the grounding member 53. Therefore, the structure can be simplified compared to when a mechanism for grounding the rotor 30 and a mechanism for grounding the driven rotor 37 are separately provided.

[0062] (1-14) For example, if the rotating shaft 31 is grounded by a bearing 40 provided at the end of the rotating shaft 31, the medium conveying device 21 will be enlarged in the axial direction by the size of the bearing 40. For example, if the rotating shaft 31 is grounded via an elastic material such as a leaf spring and the bearing 40, space will be required to install them. In this regard, the medium conveying device 21 can prevent the size from increasing because the rotating shaft 31 is grounded by an abutment 42 provided between the rotating body 30 and the bearing 40 in the axial direction.

[0063] (1-15) For example, if the bearing 40 is directly grounded, the member supporting the bearing 40 needs to be made of a conductive material such as metal. In this regard, the medium conveying device 21 grounds the rotating shaft 31 by the abutment portion 42. Therefore, the degree of freedom of the member supporting the bearing 40 can be improved.

[0064] (1-16) If the path forming portion 24 supporting the bearing 40 is made of a conductive material such as metal, the path forming portion 24 becomes heavy. This makes it difficult to move the path forming portion 24. In this regard, the rotating shaft 31 is grounded via the abutment portion 42 and the grounding member 53. Therefore, since the path forming portion 24 does not need to be made of a conductive material, the path forming portion 24 can be made lighter, and the degree of freedom in design can be increased based on the weight.

[0065] (1-17) For example, when the ground contact member 53 is brought into contact with the end surface of the rotating shaft 31, it is necessary to apply grease to the end surface. However, when the path forming portion 24 of the rotating shaft 31 is positioned in the open position, the end surface is exposed to the outside. Therefore, if grease is applied to the end surface, there is a risk that the user will come into contact with the grease. In this regard, the contact portion 42 is provided between the rotating body 30 and the bearing 40, which reduces the risk that the user will come into contact with the grease.

[0066] (1-18) The path forming portion 24 is non-conductive. Therefore, when the bearing 40 is attached to the path forming portion 24, the bearing 40 cannot be grounded. In contrast, the abutting portion 42 abuts against the rotating shaft 31. Therefore, even if the path forming portion 24 is non-conductive, the rotating shaft 31 can be grounded via the abutting portion 42.

[0067] (1-19) One rotating body 30 is provided in the center in the width direction X. Therefore, space tends to be generated on either side of the rotating body 30 in the width direction X. In the medium conveying device 21, the abutment portion 42 and the grounding member 53 are provided in the space on either side of the rotating body 30. Therefore, by making effective use of the space, it is possible to prevent the device from becoming large.

[0068] [Example of change] This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility.

[0069] As shown in FIG. 8 , the grounding member 53 may be located between the flange portion 43 and the holding portion 50. The grounding member 53 may contact the flange portion 43 and the holding portion 50. The grounding member 53 may be press-fitted between the holding portion 50 and the flange portion 43 in a bent state. Pressing the grounding member 53 allows the grounding member 53 and the abutment portion 42 to abut stably. Sandwiching the grounding member 53 between the flange portion 43 and the holding portion 50 allows the grounding member 53 to abut stably with the flange portion 43. The grounding member 53 fills the gap in the abutment portion 42, thereby suppressing rattling of the abutment portion 42.

[0070] 8, the grounding member 53 is press-fitted so as to extend along the X-axis direction, but this is not limiting. That is, the grounding member 53 may be press-fitted along the Z-axis direction. Also, the grounding member 53 may be press-fitted along a direction other than the X-axis direction or the Z-axis direction.

[0071] The holding portion 50 may be provided as a member separate from the path forming portion 24 . The retaining portion 50 may be provided on a surface other than the back surface 24b of the path forming portion 24, as long as it is provided on the side opposite to the path surface 24a. For example, it may be provided on a surface along the YZ plane of the path forming portion 24.

[0072] The bearing 40 may be provided on a surface other than the back surface 24b of the path forming portion 24, as long as the bearing 40 is provided on a surface other than the path surface 24a. In the axial direction of the rotating shaft 31, the plurality of bearings 40 may be located on both sides of the rotating body 30.

[0073] The holding portion 50 may limit the rotation of the abutting portion 42 by, for example, fitting a protrusion into a groove formed in the abutting portion 42. The holding portion 50 may limit the rotation of the abutting portion 42 by friction with the abutting portion 42. The holding portion 50 may be fixed to the abutting portion 42. The holding portion 50 may limit the rotation of the abutting portion 42 by being adhered to the abutting portion 42.

[0074] The flat surface 48 of the contact portion 42 may be positioned downward. The flat surface 48 may be in contact with the rear surface 24b of the path forming portion 24. The grounding member 53 may limit the rotation of the contact portion 42 by pressing the flat surface 48 of the contact portion 42 against the rear surface 24b of the path forming portion 24.

[0075] The flat surface 48 may be provided on the flange portion 43. The retaining portion 50 may limit the rotation of the flange portion 43. At least one of the ring portion 44 and the flange portion 43 may be an oval or rectangular tube.

[0076] The rotating body 30 may be a roller that is driven to rotate. For example, at least one of the feed roller 28, the retard roller 33, and the transport roller 36 may be a rotating body.

[0077] The rotating body 30 may be a roller that rotates in response to the medium 15 being transported. The rotating body 30 may be an endless belt that transports the medium 15. The rotating shaft 31 may rotate the belt.

[0078] The grounding member 53 may be in contact with the contact portion 42 in a state where it is not elastically deformed. The grounding member 53 may not bias the contact portion 42. The grounding member 53 may be fixed to the contact portion 42.

[0079] The path forming portion 24 may be provided immovably. The path forming portion 24 may be slidably moved between the open position and the closed position. The path forming portion 24 may be detachably provided with respect to the main body.

[0080] The tip of the holding portion 50 may be located below the ground contact member 53 . The contact portion 42 does not have to have the flange portion 43. The contact portion 42 does not have to have the flat surface 48.

[0081] The holding portion 50 may hold the contact portion 42 rotatably. The bearing 40 may be provided separately from the path forming portion 24 . The medium transport device 21 may be configured without the path forming unit 24. The medium transport device 21 may transport the medium 15 by sandwiching the medium 15 between the transport roller 36 and the driven rotor 37 and passing it on to the next transport roller 36 and driven rotor 37.

[0082] The contact portion 42 does not have to have the hole 45. The contact portion 42 does not have to surround the periphery of the rotation shaft 31. For example, the contact portion 42 may be in a semi-ring shape. The medium transport device 21 may transport the medium 15 to be printed. The rotating body 30 may be a roller that transports the medium 15 to the printing unit 12. The rotating body 30 may be a roller that transports the printed medium 15.

[0083] The medium transport device 21 may be a device that sends the medium 15 printed by the printing device 11 to a post-processing device that performs post-processing on the medium 15. The rotating body 30 may be a roller that sends the medium 15 to a post-processing device that performs post-processing. The rotating body 30 may be a roller that sends the post-processed medium 15.

[0084] The printing device 11 is not limited to an inkjet printer, but may be a laser printer, a thermal printer, a dot matrix printer, a digital printing machine, or the like. The printing device 11 may be a liquid ejection device that prints by ejecting or discharging a liquid other than ink. The liquid ejected as minute droplets from a liquid ejection device may be in the form of granules, tears, or strings. The term "liquid" as used herein refers to any material that can be ejected from a liquid ejection device. For example, the term "liquid" refers to any substance in its liquid phase, including fluids such as high or low viscosity liquids, sols, gel water, other inorganic solvents, organic solvents, solutions, liquid resins, liquid metals, and metal melts. The term "liquid" refers not only to a single state of matter, but also to solid functional material particles, such as pigments and metal particles, dissolved, dispersed, or mixed in a solvent. Typical examples of liquids include inks and liquid crystals, as described in the above embodiments. Here, "ink" encompasses various liquid compositions, such as general water-based inks and oil-based inks, as well as gel inks and hot-melt inks. Specific examples of liquid ejection devices include devices that eject liquids containing dispersed or dissolved materials such as electrode materials and color materials used in the manufacture of liquid crystal displays, electroluminescent displays, surface-emitting displays, and color filters. The liquid ejection device may be a device that ejects bioorganic materials used in biochip manufacture, a device used as a precision pipette to eject sample liquids, a textile printing device, a microdispenser, or the like. The liquid ejection device may be a device that injects lubricating oil with pinpoint accuracy onto precision machinery such as watches and cameras, or a device that ejects transparent resin liquids such as ultraviolet-curing resins onto substrates to form micro-hemispherical lenses, optical lenses, etc. used in optical communication elements, etc. The liquid ejection device may also be a device that ejects etching liquids such as acids or alkalis to etch substrates, etc.

[0085] [Definition] The phrase "at least one" as used herein means "one or more" of the desired options. As an example, the phrase "at least one" as used herein means "only one option" or "both of two options" when the number of options is two. As another example, the phrase "at least one" as used herein means "only one option," "any combination of two options," or "any combination of three or more options" when the number of options is three or more.

[0086] [Note] The technical concepts and effects that can be understood from the above-described embodiment and modified examples will be described below.

[0087] (A) The medium conveying device comprises a rotating body that rotates in contact with the medium, a conductive rotating shaft to which the rotating body is attached and which rotates the rotating body, a bearing that rotatably holds the rotating shaft, a conductive abutment portion that is provided between the rotating body and the bearing in the axial direction of the rotating shaft and can abut against the rotating shaft, and a grounding member that grounds the abutment portion.

[0088] According to this configuration, the abutment portion can abut against the rotating shaft. Abutment refers to a state in which one abuts the other, resulting in conductive contact. In other words, the abutment portion is electrically connected to the rotating shaft when it abuts against the rotating shaft. The grounding member grounds the abutment portion. Grounding the rotating shaft by an abutment portion separate from the bearing can reduce design constraints.

[0089] (B) In the medium transport device described in (A), the contact portion may have a hole formed therein, the hole having a diameter larger than the diameter of the rotary shaft. For example, if the contact portion is misaligned with the rotating shaft, the contact between the contact portion and the rotating shaft may be released. To address this issue, the contact portion has a hole with a diameter larger than that of the rotating shaft. In other words, the rotating shaft can be inserted into the hole in the contact portion. Therefore, the contact portion and the rotating shaft can be stably contacted.

[0090] (C) The medium conveying device described in (A) or (B) may further include a path forming section that forms a conveying path along which the medium is conveyed, the path forming section having a path surface that forms the conveying path, and the abutment section may be provided on the opposite side of the path forming section from the path surface.

[0091] According to this configuration, the contact portion is provided on the opposite side of the path forming portion from the path surface. By effectively utilizing the space created by providing the path forming portion, it is possible to prevent the device from becoming large.

[0092] In the medium transport device described in (D) and (C), the bearing may be provided on a back surface of the path forming portion opposite to the path surface, and the path forming portion may be non-conductive. According to this configuration, the bearing is provided on the back surface of the path forming portion. The back surface is the surface opposite to the path surface. By effectively utilizing the space created by providing the path forming portion, it is possible to prevent the device from becoming large.

[0093] In the medium conveying device described in (E)(C) or (D), the abutment portion has a ring portion in which a hole having a diameter larger than the diameter of the rotating shaft is formed, and a flange portion protruding from the ring portion in the radial direction of the hole, and the path forming portion may have a holding portion that holds the flange portion.

[0094] According to this configuration, the abutment portion has a ring portion and a flange portion. The diameter of the hole formed in the ring portion is larger than the diameter of the rotating shaft. Therefore, the abutment portion is movable in the axial direction relative to the rotating shaft inserted into the hole. In this regard, the path forming portion has a holding portion. The holding portion holds the flange portion. Therefore, the axial movement of the abutment portion can be limited.

[0095] In the medium transport device described in (F) and (E), the holding portion may hold the contact portion so that it cannot rotate. For example, rotation of the contact portion may cause abnormal noise. In this regard, with this configuration, the holding portion holds the contact portion so that it cannot rotate, thereby suppressing the generation of abnormal noise that may accompany rotation of the contact portion.

[0096] In the medium transport device described in (G) and (F), the outer peripheral surface of the ring portion may include a cylindrical surface and a flat surface, and the holding portion may have a stopper that contacts the flat surface. For example, if the stopper is to contact a cylindrical surface and prevent the contact portion from rotating by friction, the stopper must be pressed against the cylindrical surface with a large force. In contrast, with this configuration, the stopper contacts a flat surface, making it easy to prevent the contact portion from rotating.

[0097] In the medium transport device described in (H), (F), or (G), the grounding member may be located between the flange portion and the holding portion and may be in contact with the flange portion and the holding portion. According to this configuration, the grounding member is positioned between the flange portion and the holding portion. By sandwiching the grounding member between the flange portion and the holding portion, the grounding member can be brought into stable contact with the flange portion.

[0098] In the medium transport device described in (I)(C) to (H), the grounding member may be elastic and urge the abutment portion toward the rotation axis, the path forming portion may have a holding portion that holds the abutment portion, and the holding portion may hold the abutment portion so that it can be displaced in the urging direction in which the grounding member urges the abutment portion.

[0099] With this configuration, the ground contact member biases the displaceable contact portion toward the rotation shaft, thereby enabling stable contact between the ground contact member and the contact portion, and between the contact portion and the rotation shaft.

[0100] In the medium transport device described in (J)(I), the holding portion may extend further in a direction opposite to the biasing direction than the grounding member. With this configuration, the holding portion extends further in the direction opposite to the biasing direction than the ground contact member, which reduces the risk that the abutment portion, which is biased in the biasing direction by the ground contact member, will come off the holding portion.

[0101] In the medium transport device described in (K)(A) to (J), the bearing is provided in the path forming section, the path forming section is movable between a closed position that forms the transport path and an open position that exposes the path surface, and the grounding member may ground the abutment portion when the path forming section is positioned in the closed position.

[0102] According to this configuration, the path forming portion is movable. The bearing is provided on the path forming portion. Therefore, the rotating shaft held by the bearing moves together with the path forming portion. The structure for grounding the moving rotating shaft cannot be fixed. The grounding member grounds the contact portion while the path forming portion forms the transport path. Therefore, the influence of the electrically charged rotating body on the medium on the transport path can be reduced.

[0103] (L) In the medium transport device described in (A) to (G), the grounding member may be elastic and bias the contact portion toward the rotation shaft. With this configuration, the ground contact member biases the contact portion toward the rotating shaft. That is, the ground contact member presses the contact portion against the rotating shaft. Therefore, the ground contact member, the contact portion, and the rotating shaft can be stably contacted with each other.

[0104] In the medium transport device described in (M)(A) to (L), the rotating body may be a separation roller that separates multiple overlapping media, and may be detachable from the rotating shaft on the side opposite the contact portion.

[0105] For example, if the separation roller deteriorates, there is a risk that media may be transported while overlapping. In this regard, with this configuration, the rotating body, which is the separation roller, can be attached and detached from the side opposite the contact part. Therefore, the rotating body can be easily replaced while the contact part remains in contact with the rotation shaft.

[0106] (N) The medium conveying device described in (A) to (M) may further include a driven rotor that rotates in response to the medium being conveyed, a conductive support shaft that rotatably supports the driven rotor, and a conductive member that provides electrical conductivity between the support shaft and the abutment portion.

[0107] With this configuration, the conductive member electrically connects the support shaft and the contact portion. That is, the driven rotor is grounded via the support shaft, the conductive member, the contact portion, and the grounding member. This simplifies the structure compared to when a mechanism for grounding the rotor and a mechanism for grounding the driven rotor are separately provided.

[0108] (O) An image reading device includes a medium conveying device including a rotating body that rotates in contact with a medium, a conductive rotating shaft to which the rotating body is attached and which rotates the rotating body, a bearing that rotatably holds the rotating shaft, a conductive abutment portion that is provided between the rotating body and the bearing in the axial direction of the rotating shaft and can abut against the rotating shaft, and a grounding member that grounds the abutment portion, and a reading unit that reads an image on a medium conveyed by the medium conveying device.

[0109] This configuration can achieve the same effects as the medium transport device described above. (P) A printing device includes the image reading device described in (O) and a printing unit that prints an image read by the image reading device.

[0110] This configuration can achieve the same effects as the medium transport device described above. [Explanation of symbols]

[0111] 11...printing device, 12...printing unit, 13...image reading device, 15...medium, 17...feed tray, 18...ejection tray, 20...reading unit, 21...medium conveying device, 23...conveying path, 24...path forming unit, 24a...path surface, 24b...rear surface, 26...feeding unit, 27...feeding shaft, 28...feeding roller, 29...frame body, 30...rotating body, 31...rotating shaft, 31f...first end, 31s...second end, 32...drive gear, 33...retard roller -, 35...conveying portion, 36...conveying roller, 37...driven rotating body, 38...support shaft, 40...bearing, 42...contact portion, 43...flange portion, 44...ring portion, 45...hole, 47...cylindrical surface, 48...flat surface, 50...holding portion, 51...stopper, 53...grounding member, 54...fixed portion, 55...movable portion, 55a...torsion spring portion, 55b...cantilever spring portion, 57...conductive member, 58...coil spring, 59...wire material, D...conveying direction, X...width direction.

Claims

1. a rotating body that rotates in contact with the medium; a conductive rotating shaft to which the rotating body is attached and which rotates the rotating body; a bearing that rotatably holds the rotary shaft; a conductive contact portion provided between the rotor and the bearing in an axial direction of the rotating shaft and capable of contacting the rotating shaft; a grounding member for grounding the contact portion; A medium transport device comprising:

2. The medium transport device according to claim 1 , wherein the contact portion has a hole formed therein, the hole having a diameter larger than a diameter of the rotation shaft.

3. a path forming unit that forms a transport path along which the medium is transported; the path forming portion has a path surface that forms the transport path, The medium transport device according to claim 1 , wherein the contact portion is provided on an opposite side of the path forming portion from the path surface.

4. the bearing is provided on a back surface of the path forming portion opposite to the path surface, The medium transport device according to claim 3 , wherein the path forming portion is non-conductive.

5. The abutment portion is a ring portion having a hole formed therein with a diameter larger than that of the rotary shaft; a flange portion protruding from the annular portion in a radial direction of the hole; and The medium transport device according to claim 3 , wherein the path forming portion has a holding portion that holds the flange portion.

6. The medium transport device according to claim 5 , wherein the holding portion holds the contact portion so that it cannot rotate.

7. The outer peripheral surface of the ring portion includes a cylindrical surface and a flat surface, The medium transport device according to claim 6 , wherein the holding portion has a stopper that comes into contact with the flat surface.

8. The medium transport device according to claim 6 , wherein the grounding member is located between the flange portion and the holding portion and is in contact with the flange portion and the holding portion.

9. The grounding member is It has elasticity, the abutment portion is biased toward the rotation shaft, the path forming portion has a holding portion that holds the abutment portion, 4. The medium transport device according to claim 3, wherein the holding portion holds the contact portion so as to be displaceable in a biasing direction in which the grounding member biases the contact portion.

10. 10. The medium transport device according to claim 9, wherein the holding portion extends further in the direction opposite to the biasing direction than the grounding member.

11. the bearing is provided in the path forming portion, the path forming unit is movable between a closed position at which the transport path is formed and an open position at which the path surface is exposed, 11. The medium transport device according to claim 3, wherein the grounding member grounds the contact portion when the path forming portion is in the closed position.

12. The grounding member is It has elasticity, 8. The medium transport device according to claim 1, wherein the contact portion is biased toward the rotation shaft.

13. A media transport device described in any one of claims 1 to 10, characterized in that the rotating body is a separation roller that separates multiple overlapping media, and is detachable from the opposite side of the contact portion to the rotating shaft.

14. a driven rotor that rotates in response to the medium being conveyed; a conductive support shaft that rotatably supports the driven rotor; a conductive member for electrically connecting the support shaft and the abutment portion; The medium transport device according to any one of claims 1 to 10, further comprising:

15. a rotating body that rotates in contact with the medium; a conductive rotating shaft to which the rotating body is attached and which rotates the rotating body; a bearing that rotatably holds the rotary shaft; a conductive contact portion provided between the rotor and the bearing in an axial direction of the rotating shaft and capable of contacting the rotating shaft; a grounding member for grounding the contact portion; a medium transport device comprising: a reading unit that reads an image on a medium conveyed by the medium conveying device; An image reading device comprising:

16. The image reading device according to claim 15; a printing unit that prints the image read by the image reading device; A printing device comprising:

Images