JP6627381B2 - Transport device and image recording device - Google Patents

Description

  The present invention relates to a conveyance device that conveys a sheet along a conveyance path, and an image recording device including the conveyance device and capable of recording an image on a sheet.

  2. Description of the Related Art A transport device that transports a sheet along a transport path is known. An example of an apparatus including a transport device is an image recording apparatus that records an image on a sheet. The image recording apparatus is provided with a plurality of driving units driven by a motor. An example of the driving unit is a roller. The rollers convey the sheet by rotating.

  In view of recent demands for downsizing and cost reduction of image recording apparatuses, it is preferable that the number of motors mounted on the image recording apparatus is small. That is, it is preferable that the plurality of driving units provided in the image recording apparatus are driven by a common motor. In addition, with the recent increase in the number of functions of the image recording apparatus, when a part of the plurality of driving units is driven, a configuration in which the remaining part is driven or stopped is required. For example, there is a demand for a configuration in which when some of the plurality of rollers rotate forward, the remaining rollers rotate reversely, and when some of the plurality of rollers rotate, the remaining rollers stop.

  The image recording apparatus disclosed in Patent Literature 1 includes a discharge roller that guides a sheet on which an image is recorded by a recording unit to a discharge tray, and a transport roller that guides the sheet to a recording unit. In addition, the image recording apparatus includes two drive transmission units (a first drive transmission unit and a second drive transmission unit) that transmit drive from a motor from a transport roller to a discharge roller, and a second drive transmission unit. And a switching unit for switching whether to transmit the drive from the motor. The first drive transmission unit includes a one-way clutch to transmit only forward rotation of the motor from the transport roller to the discharge roller. The second drive transmission unit transmits only the reverse rotation of the motor from the transport roller to the discharge roller by including a planetary gear mechanism including a sun gear and a planetary gear, and a transmission gear. That is, in the second drive transmission unit, the planetary gear meshes with the transmission gear when the transport roller is rotating reversely, and the planetary gear separates from the transmission gear when the transport roller is rotating forward. As described above, while the image recording apparatus has a configuration in which the first drive transmission unit and the second drive transmission unit can transmit the forward rotation and the reverse rotation of the motor from the transport roller to the discharge roller, the switching unit switches the rotation of the motor from the motor. By interrupting the transmission of the drive to the second drive transmission unit, the discharge roller can be stopped while rotating the transport roller.

JP 2013-203503 A

  However, in the case of the image recording device disclosed in Patent Literature 1, the following problem may occur. When the rotation of the motor is switched from the reverse rotation to the normal rotation in a state where the reverse rotation of the motor can be transmitted from the transport roller to the discharge roller by the second drive transmission unit, the planetary gear moves away from the transmission gear to cause the second drive. While the transmission of the drive to the discharge roller via the transmission unit is cut off, the transmission of the drive to the discharge roller via the first drive transmission unit becomes possible. At this time, the forward rotation of the motor is transmitted through the first drive transmission unit and the discharge roller to a transmission gear that is part of the second drive transmission unit and normally transmits the reverse rotation of the motor to the discharge roller. It is possible.

  Then, when the rotation of the motor is switched from the reverse rotation to the forward rotation, the timing of transmission of the drive of the motor to the discharge roller via the first drive transmission unit is earlier than the timing at which the planetary gear separates from the transmission gear. In this case, the transmission gear tends to rotate by the forward rotation of the motor transmitted through the first drive transmission unit and the discharge roller while being engaged with the planetary gear. As a result, the planet gear cannot be separated from the transmission gear. As a result, the load on the motor increases, and the motor is locked and cannot be rotated.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a device capable of preventing a motor that applies rotation to a roller from being locked.

  (1) A transport device according to the present invention includes a motor that rotates forward and reverse, a driving unit that transmits and drives at least one of the forward rotation and the reverse rotation of the motor from the motor, and a first unit that transports a sheet. A first roller provided in a conveyance path, and one of forward rotation and reverse rotation of the motor is transmitted from the drive unit to the first roller, and the other of the forward rotation and reverse rotation of the motor is transmitted from the drive unit to the first roller. A first drive transmission mechanism that does not transmit to the rollers, and the other of normal rotation or reverse rotation of the motor is transmitted from the driving unit to the first roller, and one of normal rotation and reverse rotation of the motor is transmitted from the driving unit to the first roller. And a second drive transmission mechanism that does not transmit to the rollers. The second drive transmission mechanism receives one of forward rotation and reverse rotation of the motor from the drive unit and rotates in a first rotation direction, and receives the other of forward rotation and reverse rotation of the motor from the drive unit. A sun gear rotating in a second rotation direction opposite to the first rotation direction; an arm rotatably supported by the sun gear; and an arm rotatably supported by the sun gear while being engaged with the sun gear. A planet gear that can revolve around the sun gear, a transmission gear that can mesh with the planet gear, and that transmits the rotation of the motor transmitted from the planet gear to the first roller; A torque limiter that is provided between the planetary gear and the first roller in a transmission path of the rotation of the motor and has a first rotating body and a second rotating body that can mutually transmit the rotation of the motor; , Comprising a. The planet gear revolves in a direction away from the transmission gear by rotation of the sun gear in the first rotation direction, and revolves in a direction meshing with the transmission gear by rotation of the sun gear in the second rotation direction. . When the torque limiter receives a second amount of torque larger than a first amount of torque required for the first roller to rotate, the first rotator or the second rotator applies a torque during a set section. The torque transmitted between the first rotator and the second rotator is less than the first amount. The set section is a section in which the first rotator or the second rotator rotates a predetermined rotation amount of less than one rotation.

  When the rotation transmitted from the motor to the drive unit changes from the other of the normal rotation and the reverse rotation to one, the rotation of the motor can be temporarily transmitted to the transmission gear via the first drive transmission mechanism and the first roller. If the timing is earlier than the timing at which the planetary gear separates from the transmission gear, the transmission gear is rotated by one of forward rotation and reverse rotation of the motor while meshing with the planetary gear. As a result, the planet gear cannot be separated from the transmission gear.

  At this time, according to this configuration, when a second amount of torque is applied to the first rotating body or the second rotating body, the torque transmitted between the first rotating body and the second rotating body decreases. As a result, the force that causes the planetary gear to separate from the transmission gear by the rotation of the sun gear in the first rotation direction to which one of the forward rotation and the reverse rotation of the motor has been transmitted via the second drive transmission mechanism is applied to the first drive transmission. One of the forward rotation and the reverse rotation of the motor transmitted through the mechanism and the first roller causes the transmission gear to have a greater force than to maintain the mesh with the planetary gear. Then, the planetary gear separates from the transmission gear. As a result, locking of the motor can be prevented.

  Further, according to the present configuration, the state in which the torque transmitted between the first rotating body and the second rotating body is less than the first amount is caused when the first rotating body or the second rotating body is reduced by the first amount of torque. Limited to rotating less than the circumference. Therefore, when the first rotating body or the second rotating body rotates less than the one rotation, the torque transmitted between the first rotating body and the second rotating body becomes at least the first amount. As a result, it becomes possible to transmit either the forward rotation or the reverse rotation of the motor from the drive unit to the first roller via the second drive transmission mechanism. At this time, since the planetary gear is already separated from the transmission gear, an excessive torque such as the second amount is not applied to the first rotating body or the second rotating body. Therefore, the motor does not lock.

  (2) When the second amount of torque is applied to the first rotator or the second rotator, the torque limiter causes a gap between the first rotator and the second rotator during the set section. Cut off the transmitted torque.

  According to this configuration, the torque transmitted between the first rotating body and the second rotating body in the set section is zero. Therefore, it is possible to increase the difference between the two forces described in (1), that is, the force that causes the planetary gear to separate from the transmission gear and the force that causes the transmission gear to maintain meshing with the planetary gear. As a result, the planetary gear can be more reliably separated from the transmission gear.

  (3) The torque limiter further includes an urging member that urges the first rotator toward the second rotator. The first rotator rotates coaxially with the second rotator, and includes a first protrusion protruding toward the second rotator in the axial direction. The second rotator includes a second protrusion protruding toward the first rotator in the axial direction. The first convex portion can abut on the second convex portion in a circumferential direction in a state where the first rotating body is urged by the urging member. The first rotating body resists the urging force of the urging member when one of the first convex portion or the second convex portion pushes the other with the second amount or more of torque along the circumferential direction. Therefore, it moves in a direction away from the second rotating body along the axial direction.

  According to this configuration, the torque limiter having the function of the configuration (1) can be realized with a simple configuration.

  (4) The surface of at least one of the first convex portion and the second convex portion facing the circumferential direction is such that the protruding tip of the first convex portion or the second convex portion having the surface is larger than the protruding base end. The surface is inclined so as to be located on the downstream side in the direction in which the surface is pushed along the circumferential direction.

  According to this configuration, the movement of the first rotating body by one of the first convex portion and the second convex portion pushing the other along the circumferential direction can be smoothly performed.

  (5) One of the first convex portion and the second convex portion is provided at equal intervals along the circumferential direction.

  According to this configuration, the amount of rotation of the first rotating body or the second rotating body corresponding to the set section can be reduced. Accordingly, after the second amount of torque is applied to the first rotating body or the second rotating body, the transmission of the other of the forward rotation and the reverse rotation of the motor from the driving unit to the first roller via the second drive transmission mechanism is performed. It is possible to shorten the time until the state becomes possible.

  (6) The other of the first and second convex portions is provided at equal intervals along the circumferential direction, and is provided in the same number as one of the first and second convex portions.

  According to this configuration, the bias in the circumferential direction of the torque transmitted between the first rotating body and the second rotating body can be reduced.

  (7) The first drive transmission mechanism rotates integrally with the first roller by transmitting one of forward rotation and reverse rotation of the motor, and transmits the other of normal rotation and reverse rotation of the motor. A one-way clutch that idles with respect to the first roller.

  According to this configuration, the first drive transmission mechanism can be realized with a simple configuration.

  (8) For example, the drive unit transmits one of the forward rotation and the reverse rotation of the motor from the motor, rotates in the direction in which the sheet is transported in the transport direction, and outputs the forward rotation or the reverse rotation of the motor from the motor. The other roller is a second roller that is transmitted and rotates in a direction to convey the sheet in a direction opposite to the conveyance direction, and the first roller is provided by the motor from the second roller via the first drive transmission mechanism. One of forward rotation and reverse rotation is transmitted, the sheet rotates in the direction of transporting the sheet in the transport direction, and the other of forward rotation and reverse rotation of the motor is transmitted from the second roller via the second drive transmission mechanism. The second roller is provided upstream of the first roller in the transport direction in the first transport path, in a direction in which the sheet is transported in a direction opposite to the transport direction.

  (9) The transfer device according to the present invention includes a first state in which transmission of rotation of the motor from the second roller to the first roller via the second drive transmission mechanism is interrupted, and a second drive transmission. The apparatus further includes a switching mechanism capable of switching a state to a second state in which rotation of the motor can be transmitted from the second roller to the first roller via a mechanism.

  According to this configuration, by setting the switching mechanism to the first state, the first roller can be stopped while rotating the second roller. For example, the first roller can be stopped while rotating the second roller in a direction for transporting the sheet in a direction opposite to the transport direction. Thus, the sheet conveyed toward the second roller abuts on the second roller that rotates in the direction that conveys the sheet in the direction opposite to the conveyance direction, thereby correcting the skew of the sheet. At this time, even if the sheet preceding the sheet is in contact with the first roller, the first roller is stopped, so that the preceding sheet is not conveyed by the first roller. Absent.

  (10) The transport device of the present invention includes a tray on which a sheet is supported, a feed roller for feeding the sheet supported by the tray toward the second roller in the transport direction, and a forward rotation of the motor. Or a third drive transmission mechanism that transmits the other of the reverse rotation from the second roller to the feed roller and does not transmit one of the forward rotation and the reverse rotation of the motor from the second roller to the feed roller. . The switching mechanism enables the rotation of the motor to be transmitted from the second roller to the feed roller via the third drive transmission mechanism in the first state, and the third drive transmission in the second state. The transmission of the rotation of the motor from the second roller to the feed roller via a mechanism is blocked.

  According to this configuration, the sheet supported by the tray is directed to the second roller by the feed roller by setting the switching mechanism to the first state and transmitting the other of the forward rotation and the reverse rotation of the motor to the second roller. Can be fed.

  (11) In the transport device of the present invention, the third roller provided on the second transport path connected to the first transport path and the forward and reverse rotations of the motor are guided to the second transport path. And a fourth drive transmission mechanism for transmitting the rotation from the second roller to the third roller as rotation for rotating the sheet in a direction in which the sheet can be conveyed. The switching mechanism interrupts transmission of rotation of the motor from the second roller to the third roller via the fourth drive transmission mechanism in the first state, and transmits the fourth drive transmission in the second state. The rotation of the motor can be transmitted from the second roller to the third roller via a mechanism.

  According to this configuration, the switching mechanism is set to the second state, and the other of the forward rotation and the reverse rotation of the motor is transmitted from the second roller to the third roller via the fourth drive transmission mechanism, thereby guiding the motor to the second conveyance path. The conveyed sheet can be conveyed along the second conveyance path by the third roller. In particular, in the case where the transport device also has the configuration of (10), depending on the state of the switching mechanism, the feeding of the sheet by the feed roller and the transport of the sheet along the second transport path by the third roller are performed. Can be performed separately.

  (12) The transfer device of the present invention further includes a fourth roller provided downstream of the first roller in the transfer direction in the first transfer path. The second transport path includes the first transport path at a first connection position between the first roller and the fourth roller and a second connection position upstream of the second roller in the transport direction. Is connected to The first drive transmission mechanism transmits one of forward rotation and reverse rotation of the motor from the second roller to the fourth roller via the first roller. The second drive transmission mechanism transmits the other of the forward rotation and the reverse rotation of the motor from the second roller to the fourth roller via the first roller.

  According to this configuration, the portion from the first roller to the fourth roller in the drive transmission paths of the first drive transmission mechanism and the second drive transmission mechanism can be shared. Thereby, the space occupied by the first drive transmission mechanism and the second drive transmission mechanism can be reduced.

  (13) For example, the first drive transmission mechanism includes a first pulley that rotates in association with the rotation of the second roller, a second pulley that rotates in conjunction with the first roller by rotating, A third pulley that rotates in conjunction with the rotation of the second pulley, a fourth pulley that rotates in conjunction with the fourth roller by rotating, and a third pulley that is wound around the first and second pulleys. A second belt wound around the third pulley and the fourth pulley, wherein the second drive transmission mechanism includes the third pulley, the fourth pulley, and the second belt. And

  (14) The first drive transmission mechanism transmits the rotation of the motor to the first roller from one end in the axial direction of the first roller. The second drive transmission mechanism transmits the rotation of the motor to the first roller from the other end of the first roller in the axial direction.

  According to this configuration, since the first drive transmission mechanism and the second drive transmission mechanism do not interfere, the configuration of each drive transmission mechanism can be simplified.

  (15) The present invention can also be regarded as an image recording device including the transport device according to (1) to (14) and a recording unit provided on the first transport path and recording an image on a sheet. .

  (16) The recording unit may be provided upstream of the first roller in the transport direction.

  ADVANTAGE OF THE INVENTION According to this invention, lock of the motor which gives rotation to a roller can be prevented.

FIG. 1 is a perspective view of the multifunction peripheral 10. FIG. 2 is a longitudinal sectional view schematically showing the internal structure of the printer unit 11. FIG. 3 is a plan view of the carriage 23 and the guide rails 43 and 44. 4A and 4B are perspective views of the switching mechanism 170, where FIG. 4A shows a first state and FIG. 4B shows a second state. FIGS. 5A and 5B are schematic diagrams of the first transmission unit 74 and the third transmission unit 85. FIG. 5A illustrates a state in which the transport motor 102 is rotated forward, and FIG. 5B illustrates a state in which the transport motor 102 is rotated reversely. Show. 6A and 6B are schematic diagrams of the first transmission unit 74, the second transmission unit 149, and the fourth transmission unit 140, wherein FIG. 6A illustrates a state in which the transport motor 102 is normally rotated, and FIG. 10 shows a state in which 102 is reversed. FIG. 7 is a plan view of the drive transmission mechanism 70 and the rollers 60, 62, and 45. FIG. 8 is a block diagram of the printer unit 11. FIG. 9 is a flowchart of the image recording process. FIG. 10A is a front view of the gear 154, and FIG. 10B is a perspective view of the gear 154. FIG. 11 is an exploded perspective view of the gear 154.

  Hereinafter, embodiments of the present invention will be described. The embodiment described below is merely an example of the present invention, and it goes without saying that the embodiment of the present invention can be appropriately changed without changing the gist of the present invention. In the following description, the upward direction 4 and the downward direction 5 are defined based on the state in which the multifunction peripheral 10 is installed so as to be usable (the state in FIG. 1), and the surface on which the opening 13 is provided is defined as the front surface 104. A front direction 6 and a rear direction 7 are defined, and a right direction 8 and a left direction 9 are defined when the MFP 10 is viewed in the rear direction 7. The upward direction 4 and the downward direction 5 are opposite directions. The front direction 6 and the rear direction 7 are opposite directions. The right direction 8 and the left direction 9 are opposite directions. The upward direction 4, the forward direction 6, and the right direction 8 are orthogonal to each other.

[Overall Configuration of MFP 10]
As shown in FIG. 1, the multifunction peripheral 10 (an example of an image recording apparatus) is formed substantially in a rectangular parallelepiped. The multifunction peripheral 10 has a printer unit 11 that records an image on a sheet 12 (see FIG. 2) by an ink jet recording method at a lower part. The multifunction peripheral 10 has various functions such as a facsimile function and a print function. Note that the printer unit 11 may record an image on the sheet 12 using, for example, an electrophotographic method other than the ink jet recording method.

  As shown in FIG. 2, the printer unit 11 includes a transport device, a recording unit 24, and a platen 42. The transport device includes a feed unit 15, a feed tray 20 (an example of a tray), a discharge tray 21, a transport unit 54, a discharge unit 55, a reversing unit 56, a re-transport unit 57, a transport motor 102 (An example of a motor, see FIG. 7) and a drive transmission mechanism 70 (see FIG. 7).

[Feeding tray 20, discharging tray 21]
As shown in FIGS. 1 and 2, the feed tray 20 is inserted in the rearward direction 7 through the opening 13 formed in the front of the printer unit 11, and is removed in the frontward direction 6. The feed tray 20 supports a plurality of stacked sheets 12. The discharge tray 21 is arranged above the feed tray 20. The discharge tray 21 supports the sheet 12 discharged by the reversing unit 56 through the opening 13.

[Feeding unit 15]
As illustrated in FIG. 2, the feeding unit 15 includes a feeding roller 25, a feeding arm 26, and a shaft 27. The feed roller 25 is rotatably supported at the tip of the feed arm 26. The feed roller 25 rotates in a direction of transporting the paper 12 supported by the feed tray 20 in the first transport direction 16A (an example of the transport direction) by the reverse rotation of the transport motor 102 (see FIG. 7). The first transport direction 16A is a direction along a first transport path 65, which will be described later, and is shown by an alternate long and short dash line arrow in FIG. The paper 12 conveyed by the feed tray 20 in the first conveyance direction 16 </ b> A is directed to the conveyance unit 54 arranged in the first conveyance path 65. The feeding arm 26 is rotatably supported by a shaft 27 supported by a frame of the printer unit 11.

  In the following description, the rotation of the feed roller 25 in the direction of transporting the paper 12 in the first transport direction 16A is referred to as forward rotation.

[First Transport Path 65, Second Transport Path 66]
As shown in FIG. 2, a first transport path 65 and a second transport path 66 through which the paper 12 passes are formed inside the printer unit 11. The first transport path 65 refers to a space defined by the guide members 18 and 19 facing each other at a predetermined interval inside the printer unit 11.

  The first transport path 65 includes a curved transport path and a linear transport path that extends linearly. The curved conveyance path is a path that makes a U-turn while extending upward from below at the rear of the printer unit 11. The linear transport path is a path from the transport unit 54 to the discharge tray 21 via the recording unit 24. In addition, the discharge unit 55 and the reversing unit 56 according to the present embodiment are arranged in a straight conveyance path of the first conveyance path 65.

  Note that the first transport path 65 is not limited to the configuration including the curved transport path and the linear transport path as shown in FIG. For example, the first transport path 65 may be constituted only by a straight transport path.

  The second transport path 66 indicates a space defined by the guide members 29 and 30 facing each other at a predetermined interval inside the printer unit 11. The second transport path 66 is a path for turning the sheet 12 on which the image is recorded by the recording unit 24 upside down and reaching the recording unit 24 again. The second transport path 66 according to the present embodiment branches off from the first transport path 65 at a branch position 66A (an example of a first connection position), and branches at the junction position 66B (an example of a second connection position). To join. The branch position 66A is located downstream of the recording unit 24 in the first transport direction 16A. The junction position 66B is located upstream of a first sensor 120 described later in the first transport direction 16A. The second transport direction 16B of the sheet 12 in the second transport path 66 is indicated by a two-dot chain line arrow in FIG.

[Conveying unit 54, discharging unit 55, reversing unit 56, re-conveying unit 57]
As shown in FIG. 2, the transport unit 54 is disposed between the first sensor 120 and the recording unit 24 on the first transport path 65. The transport unit 54 includes a transport roller 60 (an example of a drive unit and a second roller) and a pinch roller 61 facing each other. The transport roller 60 is driven by a transport motor 102. The pinch roller 61 rotates with the rotation of the transport roller 60.

  The discharge unit 55 is disposed between the recording unit 24 and the branch position 66A in the first transport path 65. The discharge unit 55 includes a discharge roller 62 (an example of a first roller) and a spur 63 that face each other. The discharge roller 62 is driven by the transport motor 102. The spur 63 rotates with the rotation of the discharge roller 62.

  The reversing section 56 is disposed downstream of the branch position 66A in the first transport path 65 in the first transport direction 16A. The reversing unit 56 includes a reversing roller 45 (an example of a fourth roller) and a spur 46 that face each other. The reversing roller 45 is driven by the transport motor 102. The spur 46 rotates with the rotation of the reversing roller 45.

  As described later, the transport roller 60, the discharge roller 62, and the reversing roller 45 are rotatable in a direction in which the paper 12 is transported in the first transport direction 16A and in a direction opposite to the direction. In the following description, among the rotations of the rollers 60, 62, and 45, rotation in the direction in which the paper 12 is transported in the first transport direction 16A is referred to as normal rotation. In addition, among the rotations of the rollers 60, 62, and 45, rotation in the direction opposite to the normal rotation is referred to as reverse rotation.

  The re-transport section 57 is disposed on the second transport path 66. The re-transport unit 57 includes a re-transport roller 68 (an example of a third roller) and a driven roller 69 that face each other. The re-transport roller 68 is driven by the transport motor 102. The driven roller 69 rotates with the rotation of the re-conveying roller 68.

  In addition, as described later, the re-conveying roller 68 is rotatable in a direction for conveying the paper 12 in the second conveying direction 16B. In the following description, the rotation of the re-transport roller 68 in the direction of transporting the sheet 12 in the second transport direction 16B is referred to as forward rotation.

[Recording unit 24]
As shown in FIG. 2, the recording section 24 is disposed on a straight transport path of the first transport path 65. In the present embodiment, the recording unit 24 is disposed between the transport unit 54 and the discharge unit 55 in the first transport path 65.

  The recording unit 24 is disposed above the platen 42 so as to face the platen 42. The platen 42 supports the sheet 12 transported by the transport unit 54 from below. The recording unit 24 includes a carriage 23 and a recording head 39.

  As shown in FIG. 3, an ink tube 32 and a flexible flat cable 33 extend from the carriage 23. The ink tube 32 supplies the ink in the ink cartridge to the recording head 39. The flexible flat cable 33 electrically connects the control board on which the control unit 130 (see FIG. 8) is mounted to the recording head 39.

  The carriage 23 is supported by guide rails 43 and 44. The guide rails 43 and 44 are spaced apart along the front direction 6 and the rear direction 7. The guide rails 43 and 44 extend in the right direction 8 and the left direction 9. The carriage 23 is connected to a known belt mechanism provided on a guide rail 44. The belt mechanism makes a peripheral movement by driving a carriage motor 103 (see FIG. 8). By the circumferential movement of the belt mechanism, the carriage 23 reciprocates in the right direction 8 and the left direction 9.

  As shown in FIG. 2, the recording head 39 is mounted on the carriage 23. A plurality of nozzles 40 are formed on the lower surface of the recording head 39. The recording head 39 ejects ink from the nozzles 40 as minute ink droplets. In the process of moving the carriage 23, the recording head 39 ejects ink droplets to the paper 12 supported by the platen 42. Thus, an image is recorded on the paper 12.

[Route switching member 41]
As illustrated in FIG. 2, the printer unit 11 includes a path switching member 41 between the discharge unit 55 and the reversing unit 56 in the first transport path 65. The path switching member 41 includes a flap 49 and a shaft 50. The flap 49 extends from the shaft 50 substantially in the first transport direction 16A. The flap 49 is rotatably supported on a shaft 50. The flap 49 is a reversing position (position shown by a solid line in FIG. 2) that closes the first transport path 65, and a discharge position (shown by a broken line in FIG. 2) that allows the paper 12 to pass on the first transport path 65. (Posture) about the shaft 50. In addition, the flap 49 may be moved to the reversing position and the discharging position by a movement other than the rotation, for example, along the upward direction 4 and the downward direction 5.

  The flap 49 in the normal state is at the inverted position due to its own weight. Note that the flap 49 may be biased to a reverse position by a spring or the like. The flap 49 is rotated around the axis 50 from the reversing position to the discharging position by being lifted by the sheet 12 conveyed in the first conveying direction 16A. Thereafter, the flap 49 guides the paper 12 conveyed in the first conveyance direction 16A. Further, the flap 49 moves from the discharge position to the reverse position by its own weight in response to the rear end (upstream end in the first transport direction 16A) of the sheet 12 transported in the first transport direction 16A reaching the branch position 66A. Rotate.

  If the reversing roller 45 of the reversing unit 56 continues to rotate forward in this state, the sheet 12 is conveyed in the first conveying direction 16A and discharged to the discharge tray 21 as described later. On the other hand, when the reversing roller 45 of the reversing unit 56 is switched from the normal rotation to the reverse rotation, the paper 12 is moved along the second conveyance path 66 with the upstream end in the first conveyance direction 16 </ b> A as a tip, as described later. It is transported in the transport direction 16B.

[First sensor 120, second sensor 122]
As shown in FIG. 2, the printer unit 11 includes a known first sensor 120 between the merging position 66 </ b> B in the first conveyance path 65 and the conveyance unit 54. The first sensor 120 is a sensor for detecting the presence of the sheet 12 at the position where the first sensor 120 is disposed. The sheet 12 conveyed by the feeding section 15 or the re-conveying section 57 passes through the position where the first sensor 120 is disposed and reaches the conveying section 54. The first sensor 120 outputs one of a high-level signal and a low-level signal (low-level signal in the present embodiment) to the control unit 130 (see FIG. 8) in accordance with the presence of the sheet 12 at the arrangement position. I do. On the other hand, the first sensor 120 outputs the other of the high-level signal and the low-level signal (high-level signal in the present embodiment) to the control unit 130 in response to the sheet 12 not being present at the arrangement position.

  Further, the printer unit 11 includes a second sensor 122 at the branch position 66A. Similarly to the first sensor 120, the second sensor 122 outputs one of a high-level signal and a low-level signal (in the present embodiment, a low-level signal) in accordance with the presence of the sheet 12 at the position where the second sensor 122 is disposed. ) To the control unit 130, and outputs the other of the high-level signal or the low-level signal (the high-level signal in the present embodiment) in accordance with the absence of the sheet 12 at the position where the second sensor 122 is disposed. Output to

[Rotary encoder 121]
As shown in FIG. 2, the printer unit 11 includes a known rotary encoder 121 that generates a pulse signal in accordance with the rotation of the transport roller 60. The rotary encoder 121 includes an encoder disk 123 and an optical sensor 124. The encoder disk 123 rotates with the rotation of the transport roller 60. The optical sensor 124 reads the rotating encoder disk 123 to generate a pulse signal, and outputs the generated pulse signal to the control unit 130.

[Drive transmission mechanism 70]
As shown in FIG. 8, the drive transmission mechanism 70 transmits the rotation of the single transport motor 102 to the feed roller 25, the transport roller 60, the discharge roller 62, the reversing roller 45, and the re-transport roller 68. The drive transmission mechanism 70 is configured by combining all or a part of a gear, a pulley, an endless annular belt, a planetary gear mechanism, a one-way clutch, and the like.

  As shown in FIGS. 5 to 7, the drive transmission mechanism 70 includes a pulley 71 that rotates integrally with the shaft of the transport motor 102, a pulley 72 that rotates integrally with the shaft 60 </ b> A of the transport roller 60, and windings around the pulleys 71 and 72. And an endless annular belt 73 that is bridged. As a result, the transport roller 60 rotates forward when the forward rotation of the transport motor 102 is transmitted, and rotates reverse when the reverse rotation of the transport motor 102 is transmitted. The transport roller 60 transports the paper 12 sandwiched between the pinch roller 61 and the paper 12 in the first transport direction 16A by rotating forward.

  As shown in FIG. 7, the drive transmission mechanism 70 includes a switching mechanism 170 that switches the transmission destination of the rotation of the transport motor 102, and the rotation of the transport motor 102 via the shafts 60 </ b> A of the transport rollers 60. 45 to 68 are provided. However, the specific configuration for transmitting the rotation of the transport motor 102 to each of the rollers 25, 60, 62, 45, and 68 is not limited to the following example. The first transmission unit 74 is an example of a first drive transmission mechanism. The second transmission unit 149 is an example of a second drive transmission mechanism. The third transmission unit 85 is an example of a third drive transmission mechanism. The fourth transmission section 140 is an example of a fourth drive transmission mechanism.

[Switching mechanism 170]
The switching mechanism 170 shown in FIGS. 4 and 7 is configured to be able to switch the rotation transmission state of the transport motor 102 between a first state and a second state.

  In the first state, the rotation of the transport motor 102 can be transmitted from the transport roller 60 to the feed roller 25 via the third transmission unit 85, and the discharge roller 62 can be transmitted from the transport roller 60 via the second transmission unit 149. The transmission of the rotation of the transport motor 102 to the reversing roller 45 is interrupted, and the transmission of the rotation of the transport motor 102 from the transport roller 60 to the re-transport roller 68 via the fourth transmission unit 140 is interrupted. It is.

  In the second state, the transmission of the rotation of the transport motor 102 from the transport roller 60 to the feed roller 25 via the third transmission unit 85 is interrupted, and the discharge roller from the transport roller 60 via the second transmission unit 149 is discharged. In this state, the rotation of the transport motor 102 can be transmitted to the transfer roller 62 and the reversing roller 45, and the rotation of the transport motor 102 can be transmitted from the transport roller 60 to the re-transport roller 68 via the fourth transmission unit 140. is there.

  The switching mechanism 170 is provided on the right side of the first transport path 65. The switching mechanism 170 includes a switching gear 171, a gear 177, two receiving gears 172A and 172B, a holding portion 173, a pressing member 175, a switching lever 176, a first spring (not shown), and a second spring. (Not shown).

  The switching gear 171 is rotatable about the support shaft 174 and is movable along the axial direction of the support shaft 174 (right direction 8 and left direction 9). The rotation of the transport motor 102 is transmitted to the switching gear 171 through the shaft 60 </ b> A of the transport roller 60 and the gear 177. The gear 177 is attached to the shaft 60A of the transport roller 60, and rotates integrally with the shaft 60A of the transport roller 60. The receiving gears 172A and 172B are rotatable coaxially along the rightward direction 8 and the leftward direction 9 below the support shaft 174, and are configured to mesh with the switching gear 171. That is, the switching gear 171 meshes with one of the receiving gears 172A, 172B by moving in the rightward direction 8 and the leftward direction 9.

  The receiving gear 172 </ b> A is a gear for transmitting the rotation of the transport motor 102 to the feed roller 25 via the third transmission unit 85. The receiving gear 172B is a gear for transmitting the rotation of the conveyance motor 102 to the discharge roller 62 and the reversing roller 45 via the second transmission unit 149, and to the re-conveyance roller 68 via the fourth transmission unit 140. is there. When switching gear 171 is engaged with receiving gear 172A, switching mechanism 170 is in the first state, and when switching gear 171 is engaged with receiving gear 172B, switching mechanism 170 is in the second state.

  The pressing member 175 is disposed to the right of the switching gear 171, and is movably inserted through the support shaft 174 along the right direction 8 and the left direction 9. Further, the pressing member 175 is rotatable about the support shaft 174. The switching lever 176 projects upward from the pressing member 175, and extends through the opening 179 of the holding portion 173 to the movement path of the carriage 23 and out of the area where the paper 12 passes. The switching gear 171 is urged rightward by a first spring (not shown), and the pressing member 175 is urged leftward by a second spring (not shown). The biasing force of the second spring is greater than the biasing force of the first spring. As a result, the switching gear 171 and the pressing member 175 are urged leftward 9 by the second spring.

  The holding section 173 is provided above the switching gear 171. An opening 179 is formed in the holding portion 173. The switching lever 176 is inserted into the opening 179 in the upward direction 4. At the edge of the opening 179, a first stopper 180, a second stopper 181 provided to the right of the first stopper 180, and an inclined surface 182 provided to the right of the second stopper 181 are formed. Have been.

  As shown in FIG. 4A, the first stopper 180 contacts the switching lever 176 when the switching gear 171 is engaged with the receiving gear 172A, that is, when the switching mechanism 170 is in the first state. . This restricts the switching gear 171 from moving leftward from the position shown in FIG. 4A by the urging force of the second spring. On the other hand, the first stopper 180 does not restrict the movement of the switching gear 171 to the right from the position shown in FIG.

  As shown in FIG. 4B, the second stopper 181 is engaged with the switching lever 176 when the switching gear 171 is engaged with the receiving gear 172B, that is, when the switching mechanism 170 is in the second state. I do. This restricts the switching gear 171 from moving leftward from the position shown in FIG. 4B by the urging force of the second spring. On the other hand, the second stopper 181 does not restrict the rightward movement of the switching gear 171 from the position shown in FIG.

  As shown in FIG. 4A, when the switching gear 171 is engaged with the receiving gear 172A, that is, when the switching mechanism 170 is in the first state, the switching lever 176 moves to the right in the carriage 23. , The switching lever 176 moves rightward against the urging force of the second spring. As a result, the pressing member 175 moves rightward integrally with the switching lever 176. When the pressing member 175 moves to the right, the switching gear 171 urged in the right direction 8 by the first spring moves to the right. When the switching lever 176 is engaged with the second stopper 181, the switching gear 171 is held in a state of being meshed with the receiving gear 172B. That is, the switching mechanism 170 is maintained in the second state (see FIG. 4B). As described above, the switching mechanism 170 changes from the first state to the second state.

  As shown in FIG. 4B, when the switching gear 171 is engaged with the receiving gear 172B, that is, when the switching mechanism 170 is in the second state, the switching lever 176 moves rightward to the carriage 23. , The switching lever 176 moves rightward against the urging force of the second spring. As a result, the pressing member 175 moves rightward integrally with the switching lever 176. When the pressing member 175 moves rightward, the switching gear 171 urged in the right direction 8 by the first spring moves rightward. At this time, the switching lever 176 moves along the inclined surface 182. As a result, the switching lever 176 rotates so that the protruding tip (upper end) moves rearward.

  In a state where the switching lever 176 is located to the right of the second stopper 181, the carriage 23 maintains contact with the switching lever 176, and the switching gear 171 is moved leftward by the urging force of the second spring. Moving is regulated.

  When the carriage 23 moves leftward and separates from the switching lever 176 in a state where the switching lever 176 is in contact with the inclined surface 182 on the right side of the position shown in FIG. It moves to the left by the urging force of the second spring. At this time, as described above, the switching lever 176 rotates so that its protruding tip moves rearward, and thus moves to the left from the second stopper 181 without engaging with the second stopper 181. As a result, the switching lever 176 moves to the left until it comes into contact with the first stopper 180. At this time, the switching gear 171 is pushed to the left by the pressing member 175 and meshes with the receiving gear 172A (see FIG. 4A). That is, the switching mechanism 170 is maintained in the first state. As described above, the switching mechanism 170 changes from the second state to the first state.

  When moving to the left, the switching lever 176 moves along the inclined surface 183 formed near the first stopper 180 at the edge of the opening 179. As a result, the switching lever 176 rotates so that its protruding tip moves forward.

[First transmission unit 74]
The first transmission unit 74 shown in FIGS. 5 and 6 transmits the forward rotation of the transport motor 102 transmitted via the shaft 60 </ b> A of the transport roller 60 to the discharge roller 62 and the reversing roller 45. As shown in FIG. 7, the first transmission unit 74 is provided on the left side of the first transport path 65. That is, the first transmission unit 74 transmits the rotation to the discharge roller 62 from the left side (an example of one end) of the discharge roller 62. Note that the position of the first transmission unit 74 is not limited to the position shown in FIG. For example, the first transmission unit 74 may be provided on the right side of the first transport path 65.

  As shown in FIGS. 5 and 6, the first transmission unit 74 includes gears 75 and 76 that mesh with each other, pulleys 77 to 80, endless annular belts 81 and 82, and a one-way clutch 83. I have. The pulley 77 is an example of a first pulley. The pulley 78 is an example of a second pulley. The pulley 79 is an example of a third pulley. The pulley 80 is an example of a fourth pulley. The belt 81 is an example of a first belt. The belt 82 is an example of a second belt.

  The gear 75 meshes with the gear 76 and rotates integrally with the shaft 60A of the transport roller 60. The gear 76 and the pulley 77 rotate coaxially and integrally. That is, the pulley 77 rotates in conjunction with the rotation of the transport roller 60. The pulley 78 is attached to a shaft 62A of the discharge roller 62 via a one-way clutch 83. That is, the rotation of the pulley 78 causes the discharge roller 62 to rotate in conjunction therewith.

  One-way clutch 83 rotates integrally with discharge roller 62 when forward rotation of transport motor 102 is transmitted. That is, the one-way clutch 83 transmits the forward rotation of the transport motor 102 transmitted to the pulley 78 to the shaft 62A of the discharge roller 62 and the pulley 79. On the other hand, the one-way clutch 83 idles with respect to the discharge roller 62 when the reverse rotation of the transport motor 102 is transmitted. That is, the one-way clutch 83 does not transmit the reverse rotation of the transport motor 102 transmitted to the pulley 78 to the shaft 62A of the discharge roller 62 and the pulley 79. A known one-way clutch 83 is used.

  The pulley 79 rotates integrally with the shaft 62A of the discharge roller 62. That is, the pulley 79 rotates in conjunction with the rotation of the pulley 78. The pulley 80 rotates integrally with the shaft 45A of the reversing roller 45. That is, when the pulley 80 rotates, the reversing roller 45 rotates in conjunction with the rotation.

  The belt 81 is wound around pulleys 77 and 78. The belt 82 is wound around pulleys 79 and 80.

  As shown in FIG. 5A, the first transmission unit 74 transmits the forward rotation of the transport motor 102 from the transport roller 60 to the discharge roller 62 and the reversing roller 45, and rotates the rollers 62 and 45 forward. Let it. On the other hand, as shown in FIG. 5B, the first transmission unit 74 does not transmit the reverse rotation of the transport motor 102 from the transport roller 60 to the discharge roller 62 and the reversing roller 45.

  As described above, the discharge roller 62 is moved in the direction in which the paper 12 sandwiched between the spur 63 and the spur 63 is transported in the first transport direction 16A by the forward rotation of the transport motor 102 being transmitted through the first transmission unit 74. Rotate. The reversing roller 45 rotates in a direction of transporting the paper 12 sandwiched between the spur 46 and the spur 46 in the first transport direction 16 </ b> A when the forward rotation of the transport motor 102 is transmitted through the first transmission unit 74. I do. Thus, the paper 12 is discharged to the discharge tray 21.

[Second transmission unit 149]
The second transmission unit 149 illustrated in FIG. 6 transmits the reverse rotation of the transport motor 102 transmitted via the shaft 60A of the transport roller 60 and the switching mechanism 170 in the second state to the discharge roller 62 and the reversing roller 45. As shown in FIG. 7, the second transmission section 149 is provided on the right side of the first transport path 65. That is, the second transmitting unit 149 transmits the rotation from the right side (an example of the other end) of the discharge roller 62 to the discharge roller 62. The position of the second transmission unit 149 is not limited to the position shown in FIG. For example, the second transmission unit 149 may be provided on the left side of the first conveyance path 65. When the second transmission unit 149 is provided on the left side of the first transport path 65, the first transmission unit 74 is preferably provided on the right side of the first transport path 65.

  As shown in FIG. 6, the second transmission unit 149 includes a gear train 150, a sun gear 151, a planetary gear 152, an arm 153, a gear 154 (an example of a transmission gear and a torque limiter), a pulley 79, 80 and a belt 82. The pulleys 79 and 80 and the belt 82 are a part of the components of the first transmission unit 74 and also a part of the components of the second transmission unit 149.

  The gear train 150 includes a plurality of gears 150A to 150D in which adjacent gears mesh with each other. Gear 150A meshes with receiving gear 172B. Sun gear 151 meshes with gear 150D. The planet gear 152 meshes with the sun gear 151 and comes into contact with and separates from the gear 154 (specifically, the rotating body 112 of the gear 154 (see FIG. 10)). One end of the arm 153 is rotatably supported by the sun gear 151, and the other end supports the planetary gear 152 so as to be able to rotate and revolve around the sun gear 151. Thereby, the planetary gear 152 revolves around the sun gear 151 while rotating by rotation of the sun gear 151.

  The gear 154 is provided between the planetary gear 152 and the discharge roller 62 in the transmission path of the rotation of the transport motor 102 in the second transmission unit 149. Accordingly, the gear 154 transmits the rotation of the transport motor 102 transmitted from the meshed planetary gear 152 to the discharge roller 62. The gear 154 will be described later in detail.

  The sun gear 151 rotates in the first rotation direction 105 indicated by an arrow in FIG. 6A by transmitting the forward rotation of the transport motor 102. Thus, the planet gear 152 revolves in the first rotation direction 105 and separates from the gear 154. As a result, the second transmission unit 149 does not transmit the forward rotation of the transport motor 102 from the transport roller 60 to the discharge roller 62 and the reversing roller 45.

  On the other hand, the sun gear 151 rotates in the second rotation direction 106 (a direction opposite to the first rotation direction 105) indicated by an arrow in FIG. Thus, the planet gears 152 revolve in the second rotation direction 106 and mesh with the gears 154. As a result, the second transmission unit 149 transmits the reverse rotation of the transport motor 102 from the transport roller 60 to the discharge roller 62 and the reverse roller 45, and reverses the rollers 62 and 45.

  In addition, the reversing roller 45 is configured to transfer the sheet 12 sandwiched between the spur 46 and the spur 46 in a direction opposite to the first conveying direction 16 </ b> A when the reverse rotation of the conveying motor 102 is transmitted through the second transmitting unit 149. To rotate. At this time, if the flap 49 is in the normal state, the paper 12 is guided to the second transport path 66 with the upstream end in the first transport direction 16A as a leading end, and moves along the second transport path 66 in the second transport direction 16B. Transported to

  The second transmission unit 149 includes a reduction unit that reduces the rotation speed of the transport roller 60 and transmits the rotation speed to the discharge roller 62. Thus, the rotation speed of the re-conveyance roller 68 can be higher than the rotation speeds of the discharge roller 62 and the reversing roller 45. As a result, it is possible to prevent the paper 12 from bending between the re-conveying roller 68 and the reversing roller 45 in the second conveying path 66. Further, when the sheet 12 is sandwiched by both the reversing unit 56 and the re-transporting unit 57 while the reversing roller 45 is rotating forward, the sheet 12 is pulled between the reversing unit 56 and the re-conveying unit 57. However, even if tension occurs, the paper 12 can be guided to the second conveyance path 66 by the re-conveyance roller 68 having a high rotation speed.

  In the present embodiment, the reduction units are the gear 150A located at the most upstream in the transmission direction from the transport roller 60 to the discharge roller 62 in the second transmission unit 149, and the gear 154 located at the most downstream in the transmission direction. The ratio (n2 / n1) of the number of teeth n1 of the gear 150A to the number of teeth n2 of the gear 154 is larger than 1. Note that the configuration of the reduction unit is not limited to the configuration described above. For example, the interval between the teeth of any of the gears (for example, gear 150B) forming second transmission portion 149 may be configured to be larger than the gears other than gear 150B forming second transmission portion 149. In this case, the gear 150B is a reduction section. Of course, the intervals between the teeth of the gears other than the gear 150B may be increased.

[Third Transmission Unit 85]
The third transmission unit 85 shown in FIG. 5 transmits the rotation of the transport motor 102 transmitted via the shaft 60 </ b> A of the transport roller 60 and the switching mechanism 170 in the first state to the feed roller 25. As shown in FIG. 5, the third transmission unit 85 includes gears 86 to 91, pulleys 92 to 95, endless annular belts 96 and 97, a sun gear 98, a planetary gear 99, and an arm 100. It is configured.

  The gear 86 meshes with the receiving gear 172A and the gear 87. The gear 87 and the pulley 92 rotate coaxially and integrally. The gear 88 and the pulley 93 rotate coaxially and integrally. The gear 89 meshes with the gear 88. The sun gear 98 rotates coaxially with the gear 89. The planet gear 99 meshes with the sun gear 98 and moves toward and away from the gear 90. One end of the arm 100 is rotatably supported by the sun gear 98, and the other end supports the planetary gear 99 so that it can rotate and revolve around the sun gear 98. Thereby, the planetary gear 99 revolves around the sun gear 98 while rotating by rotation of the sun gear 98. The gear 90 meshes with the gear 91. The gear 91 and the pulley 94 rotate coaxially and integrally. The pulley 95 rotates coaxially and integrally with the feed roller 25. The belt 96 is wound around pulleys 92 and 93. The belt 97 is wound around pulleys 94 and 95.

  As shown in FIG. 5A, the planetary gear 99 is separated from the gear 90 by the forward rotation of the transport motor 102 being transmitted to the sun gear 98. As a result, the third transmission unit 85 does not transmit the forward rotation of the transport motor 102 to the feed roller 25. On the other hand, as shown in FIG. 5B, the planetary gear 99 meshes with the gear 90 by transmitting the reverse rotation of the transport motor 102 to the sun gear 98. As a result, the third transmission unit 85 transmits the reverse rotation of the transport motor 102 to the feed roller 25. As a result, the feed roller 25 rotates forward.

[Fourth transmission unit 140]
The fourth transmission unit 140 shown in FIG. 6 transmits the rotation of the transport motor 102 transmitted via the shaft 60A of the transport roller 60 and the switching mechanism 170 in the second state to the re-transport roller 68. As shown in FIG. 6, the fourth transmission unit 140 includes a sun gear 141, planetary gears 142 and 143, arms 144 and 145, a gear train 146, and gears 147 and 148.

  Sun gear 141 meshes with receiving gear 172B. The planet gear 142 meshes with the sun gear 141 and comes into contact with and separates from the gear 146A. The planet gear 143 meshes with the sun gear 141 and comes into contact with and separates from the gear 146B. The arm 144 has one end rotatably supported by the sun gear 141 and the other end rotatably supports the planetary gear 142 around the sun gear 141 and revolves around the sun gear 141. One end of the arm 145 is rotatably supported by the sun gear 141, and the other end supports the planetary gear 143 so as to be able to rotate and revolve around the sun gear 141. The gear train 146 includes a plurality of gears 146A to 146F in which adjacent gears mesh with each other. The gear 147 rotates coaxially and integrally with the gear 146F. The gear 148 meshes with the gear 147 and rotates coaxially with the axis of the re-conveying roller 68.

  As shown in FIG. 6A, when the forward rotation of the transport motor 102 is transmitted to the sun gear 141, the planet gear 142 separates from the gear 146A, and the planet gear 143 meshes with the gear 146B. That is, the forward rotation of the transport motor 102 is transmitted from the transport roller 60 to the re-transport roller 68 via the gears 146B to 146F. On the other hand, as shown in FIG. 6B, when the reverse rotation of the transport motor 102 is transmitted to the sun gear 141, the planet gear 142 meshes with the gear 146A, and the planet gear 143 separates from the gear 146B. That is, the reverse rotation of the transport motor 102 is transmitted from the transport roller 60 to the re-transport roller 68 through the gears 146A to 146F. As a result, the re-conveyance roller 68 rotates forward regardless of whether forward rotation or reverse rotation of the conveyance motor 102 is transmitted. The re-conveying roller 68 conveys the sheet 12 sandwiched between the re-conveying roller 68 and the driven roller 69 in the second conveying direction 16B by rotating forward.

[Gear 154]
The gear 154 of the second transmission unit 149 shown in FIG. 6 has a function as a torque limiter, as described in detail below.

  As shown in FIGS. 10 and 11, the gear 154 includes two rotating bodies 111 and 112 and an urging member 113.

  The rotating body 111 (an example of a second rotating body) is fitted around the shaft 62 </ b> A of the discharge roller 62. The rotating body 111 includes a cylindrical main body 115, and a flange 116 extending from the left end of the main body 115 in the radial direction of the main body 115.

  A through-hole 117 is formed in the main body 115 along the right direction 8 and the left direction 9. The shaft 62A of the discharge roller 62 is inserted into the through hole 117. The inner diameter of the through hole 117 is slightly smaller than the outer diameter of the shaft 62A. Thus, the shaft 62A is inserted into the main body 115 while elastically deforming the main body 115. As a result, the rotating body 111 can rotate integrally with the shaft 62A of the discharge roller 62. That is, the axial direction of the rotating body 111 is a direction along the right direction 8 and the left direction 9 like the shaft 62A.

  The configuration in which the rotating body 111 can rotate integrally with the shaft 62A of the discharge roller 62 is not limited to the configuration described above. For example, the rotating body 111 may be integrally formed with the shaft 62A. In addition, for example, a convex portion formed on one of the main body 115 or the shaft 62A and a concave portion formed on the other of the main body 115 or the shaft 62A may be fitted. In this case, the inner diameter of the through hole 117 may be larger than the outer diameter of the shaft 62A.

  A convex portion 118 (an example of a second convex portion) protruding rightward 8 is formed on the right surface 116A of the flange portion 116. In the present embodiment, three convex portions 118 are provided at equal intervals along the circumferential directions 155 and 156 of the rotating body 111. The circumferential directions 155 and 156 are opposite to each other. The number of the convex portions 118 may be one or a plurality other than three. When a plurality of convex portions 118 are provided, the intervals between the convex portions 118 may not be equal.

  The protrusion 118 has two inclined surfaces 118A and 118B. The surface 118A is a surface facing the circumferential direction 155. The protruding base end of the convex portion 118 on the surface 118A is located in the circumferential direction 155 more than the protruding distal end of the convex portion 118 on the surface 118A. The surface 118B is a surface facing the circumferential direction 156. The protruding base end of the convex portion 118 on the surface 118B is located in the circumferential direction 156 more than the protruding distal end of the convex portion 118 on the surface 118B.

  The rotating body 112 (an example of a first rotating body) has a cylindrical shape in which a through hole 119 is formed along the right direction 8 and the left direction 9. A plurality of teeth are formed at equal intervals on the outer peripheral surface of the rotating body 112. That is, the rotating body 112 constitutes a gear. The rotator 112 can mesh with the planetary gear 152.

  The rotating body 112 is fitted on the main body 115 of the rotating body 111. Thus, the rotating body 112 is located to the right of the flange 116 of the rotating body 111 and faces the flange 116 of the rotating body 111 in the rightward direction 8 and the leftward direction 9. That is, the above-mentioned convex portion 118 of the rotating body 111 protrudes toward the rotating body 112.

  The inner diameter of the rotating body 112 is larger than the outer diameter of the main body 115. Thereby, the rotating body 112 can move relative to the rotating body 111 along the right direction 8 and the left direction 9. Further, the rotating body 112 rotates coaxially with the rotating body 111.

  On the left surface 112A of the rotator 112, a protrusion 126 (an example of a first protrusion) protruding in the left direction 9 is formed. That is, the protrusion 126 protrudes toward the flange 116 of the rotating body 111. In the present embodiment, three convex portions 126 are provided at equal intervals along the circumferential directions 155 and 156 of the rotating body 112. That is, the same number of the convex portions 126 as the convex portions 118 of the rotating body 111 are provided. Since the rotating body 112 rotates coaxially with the rotating body 111, the circumferential directions 155 and 156 of the rotating body 111 correspond to the circumferential direction of the rotating body 112.

  In addition, the number of the protrusions 126 may be one or a plurality other than three. Further, the number of the protrusions 126 may be the same as the number of the protrusions 118 of the rotating body 111 as in the present embodiment, or may be a different number. For example, the number of the convex portions 126 may be one and the number of the convex portions 118 may be plural, the number of the convex portions 126 may be plural and the number of the convex portions 118 may be one, As in the present embodiment, both the convex portions 126 and 118 may be plural. When a plurality of convex portions 126 are provided, the intervals between the convex portions 118 do not have to be equal.

  The protrusion 126 has two inclined surfaces 126A and 126B. The surface 126A is a surface facing the circumferential direction 156. The protruding base end of the convex portion 126 on the surface 126A is located in the circumferential direction 156 more than the protruding distal end of the convex portion 126 on the surface 126A. The surface 126B is a surface facing the circumferential direction 155. The protruding base end of the convex portion 126 on the surface 126B is located in the circumferential direction 155 more than the protruding distal end of the convex portion 126 on the surface 126B.

  As described later, the surface 126A faces the surface 118A in the circumferential directions 155 and 156. The surface 126B faces the surface 118B in the circumferential directions 155 and 156. That is, in the present embodiment, both of the two opposing surfaces in the circumferential directions 155 and 156 are inclined surfaces. However, any one of the two opposing surfaces in the circumferential directions 155 and 156 may be an inclined surface. For example, if one of the opposing surfaces 118A and 126A is inclined, the other need not be inclined.

  In the present embodiment, as shown in FIGS. 10 and 11, the convex portions 118 and 126 have a shape having inclined surfaces facing the circumferential directions 155 and 156. Is not limited to the shape shown in FIG. 10 and FIG. For example, the protrusions 118 and 126 may be semicircular when viewed in the radial direction of the rotating bodies 111 and 112.

  The biasing member 113 is a coil spring in the present embodiment. The urging member 113 urges the rotating body 112 toward the left direction 9. In other words, the urging member 113 urges the rotating body 112 toward the flange portion 116 of the rotating body 111. The urging member 113 is not limited to a coil spring, and may be, for example, a leaf spring or a torsion spring.

  The left end of the urging member 113 is in contact with the right surface 112B of the rotating body 112. The right end of the urging member 113 is in contact with the contact member 114. The contact member 114 is a member disposed to the right of the gear 154. In the present embodiment, the contact member 114 is a retaining ring attached to the shaft 62A of the discharge roller 62, but the contact member 114 is not limited to the retaining ring. For example, the contact member 114 may be a flange formed on the shaft 62A. Further, for example, the contact member 114 may be a frame of the multifunction peripheral 10 arranged to the right of the gear 154.

  When the rotating body 112 is urged by the urging member 113, the convex portion 118 of the rotating body 111 comes into contact with the left surface 112A of the rotating body 112, and the convex portion 126 of the rotating body 112 is It contacts the right surface 116A. That is, the convex portion 118 of the rotating body 111 is located between two adjacent convex portions 126 of the rotating body 112, and the convex portion 126 of the rotating body 112 is located between the two adjacent convex portions 118 of the rotating body 111. It is located between. Thus, the surface 126A faces the surface 118A in the circumferential directions 155 and 156. The surface 126B faces the surface 118B in the circumferential directions 155 and 156.

  The surface 118A and the surface 126A come into contact with each other by the rotation of the rotating body 111 in the circumferential direction 155 to which the reverse rotation of the transport motor 102 is transmitted. The rotation of the rotating body 111 in the circumferential direction 156 to which the forward rotation of the transport motor 102 is transmitted, or the rotation of the rotating body 112 in the circumferential direction 155 to which the reverse rotation of the transport motor 102 is transmitted, causes the surface 118B and the surface 118B to rotate. 126B abuts. Thus, the rotation of the transport motor 102 is transmitted from the rotating body 111 to the rotating body 112 or from the rotating body 112 to the rotating body 111. As described above, in a state where the rotating body 112 is urged by the urging member 113, the convex portions 118 and 126 can abut in the circumferential directions 155 and 156.

  The gear 154 operates as follows by being configured as described above.

  First, the operation of the gear 154 when the transport motor 102 switches from reverse rotation to normal rotation will be described. In this operation, the switching mechanism 170 is in the second state. Thus, the reverse rotation of the transport motor 102 can be transmitted to the second transmission unit 149.

  When the reverse rotation of the transport motor 102 is being transmitted, the rotating body 112 is engaged with the planetary gear 152. Accordingly, the rotating body 112 is rotated in the circumferential direction 155 by receiving the reverse rotation of the transport motor 102 from the planetary gear 152. When the rotating body 112 rotates in the circumferential direction 155, the surface 126B of the projection 126 comes into contact with the surface 118B of the projection 118 of the rotating body 111 and presses the surface 118B. Thereby, the rotating body 111 rotates in the circumferential direction 155 integrally with the rotating body 112. As a result, the shaft 62A of the discharge roller 62 that rotates integrally with the rotating body 111 also rotates in the circumferential direction 155. That is, the discharge roller 62 rotates in the reverse direction (see FIG. 6B).

  In this state, when the rotation of the conveyance motor 102 is switched from the reverse rotation to the normal rotation, the planetary gear 152 is normally separated from the rotating body 112, and then the discharge roller 62 is driven by the conveyance motor 102 via the first transmission unit 74. By transmitting the forward rotation, the forward rotation is performed. Thereby, the rotating body 111 rotates in the circumferential direction 156. Then, the surface 118B of the convex portion 118 comes into contact with the surface 126B of the convex portion 126 of the rotating body 112 and presses the surface 126B. As a result, the rotating body 112 rotates in the circumferential direction 156 integrally with the rotating body 111.

  However, when the rotation of the transport motor 102 is switched from the reverse rotation to the normal rotation, depending on the dimensional tolerance and the mounting error of the members constituting the first transmission unit 74 and the second transmission unit 149, the second transmission unit 149 does not. The timing at which the planetary gear 152 separates from the rotating body 112 may be delayed, or the timing at which the forward rotation of the transport motor 102 is transmitted to the discharge roller 60 via the first transmission unit 74 may be advanced.

  When such a timing shift occurs, when the rotation of the transport motor 102 is switched from the reverse rotation to the forward rotation, the discharge roller 62 is connected to the first transmission unit before the planetary gear 152 separates from the rotating body 112. When the forward rotation of the transport motor 102 is transmitted via the transmission 74, the transport motor 102 may rotate forward.

  When the discharge roller 62 rotates forward with the planetary gear 152 meshing with the rotating body 112, the gear 154 operates as described in detail below. First, the rotating body 111 tries to rotate in the circumferential direction 156 due to the normal rotation of the discharge roller 62. That is, the surface 118B of the convex portion 118 comes into contact with the surface 126B of the convex portion 126 of the rotating body 112 and presses the surface 126B. As a result, torque in the circumferential direction 156 acts on the rotating body 112 from the convex portion 118. However, even if torque in the circumferential direction 156 acts on the rotating body 112 from the convex portion 118, rotation of the rotating body 112 in the circumferential direction 156 is hindered by the meshed planetary gear 152. That is, the rotating body 112 cannot rotate in the circumferential direction 156. Further, the planetary gear 152 transmitted through the second transmission portion 149 to transmit the forward rotation of the transport motor 102 tries to separate from the rotating body 112, but the separation is pushed by the convex portion 118 and rotates in the circumferential direction 156. It is impeded by the torque of the rotating body 112 that is about to be used. That is, the planet gear 152 cannot be separated from the rotating body 112.

  Usually, the rollers and gears to which the rotation is transmitted from the conveyance motor 102 have a smaller torque T2 (an example of the second amount of torque) T2 (an example of the second amount of torque) generated in the conveyance motor 102 by rotation of the conveyance motor 102. (Example of the first amount of torque). That is, the torque required for rotating the rollers and gears is the torque T2. Therefore, normally, the torque T1 does not act on the rollers and gears. However, as described above, when the rotating body 112 cannot rotate, the torque T1 acts on the rotating body 112.

  Then, the surface 118B pushes the surface 126B of the projection 126 with the torque T1. Here, the urging force of the urging member 113 is set to a value larger than the torque T2 and smaller than the torque T1. Therefore, when the surface 118B pushes the surface 126B with the torque T1, the rotating body 112 moves rightward 8 against the urging force of the urging member 113. That is, the rotating body 112 moves in a direction away from the rotating body 111. Since the urging force of the urging member 113 is larger than the torque T2, when the rotating bodies 111 and 112 rotate at a constant speed, the rotating body 112 moves rightward against the urging force of the urging member 113. No move to 8.

  The surfaces 118A and 118B are inclined such that the protruding distal end of the convex portion 118 is located downstream of the protruding proximal end in the direction in which the surfaces 118A and 118B are pushed by the surfaces 126A and 126B opposed to the circumferential directions 155 and 156. I have. Also, the surfaces 126A and 126B are inclined such that the protruding distal end of the convex portion 126 is located downstream of the protruding base end in the direction in which the surfaces 126A and 126B are pushed by the surfaces 118A and 118B opposed to the circumferential directions 155 and 156. are doing. Thus, when the rotating body 112 moves in the right direction 8 against the urging force of the urging member 113, the convex portion 118 is guided along the surface 126B toward the protruding tip of the convex portion 126. As a result, the convex portion 118 gets over the convex portion 126.

  When the convex portion 118 gets over the convex portion 126, the rotating body 112 moves leftward 9 by the urging force of the urging member 113, and the rotating body 111 idles with respect to the rotating body 112. That is, when the torque T1 is applied to the rotating body 112, the torque transmitted between the rotating bodies 111 and 112 is cut off. As a result, the torque from the rotating body 112 does not act on the planetary gear 152, so that the planetary gear 152 can be separated from the rotating body 112. The separation of the planetary gear 152 from the rotating body 112 is performed during a setting section described below.

  The idling of the rotator 111 with respect to the rotator 112 is executed during the set section. That is, no torque is applied to the rotating body 112 during the set section. On the other hand, during the set section, the torque T2 is applied to the rotating body 111 that rotates integrally with the discharge roller 60. Here, the set section is a section in which the rotating body 111 rotates a predetermined rotation amount of less than one rotation by the torque T2. In the present embodiment, the predetermined rotation amount of less than one round is the rotation amount of the rotating body 111 from when the convex portion 118 gets over the convex portion 126 to when it comes into contact with the convex portion 126 again. That is, in the case where the plurality of protrusions 126 are provided, the predetermined amount of rotation is determined by the distance between two adjacent protrusions 126 along the circumferential direction 155, 156. In the case where only one projection 126 is provided, the predetermined rotation amount is determined by the distance between the surfaces 126A and 126B along the circumferential direction 155 and 156.

  When idling of the rotating body 111 with respect to the rotating body 112 is performed in the set section, the convex portion 118 comes into contact with the convex portion 126 again. At this time, the planet gear 152 has already been separated from the rotating body 112. Therefore, the rotating body 112 rotates in the circumferential direction 156 integrally with the rotating body 111 when the protrusion 126 is pressed by the protrusion 118.

  Next, the operation of the gear 154 when the transport motor 102 switches from normal rotation to reverse rotation will be described. In this operation, the switching mechanism 170 is in the second state. Thus, the reverse rotation of the transport motor 102 can be transmitted to the second transmission unit 149.

  When the forward rotation of the transport motor 102 is being transmitted, the rotating body 112 is separated from the planetary gear 152. In addition, when the forward rotation of the transport motor 102 is transmitted through the first transmission unit 74, the rotating body 111 rotates in the circumferential direction 156 integrally with the normally rotating discharge roller 62 (see FIG. 6A). ). When the rotating body 111 rotates in the circumferential direction 156, the surface 118B of the projection 118 comes into contact with the surface 126B of the projection 126 of the rotating body 112 and presses the surface 126B. As a result, the rotating body 112 rotates in the circumferential direction 156 integrally with the rotating body 111.

  In this state, when the rotation of the transport motor 102 is switched from normal rotation to reverse rotation, the one-way clutch 83 blocks transmission of the reverse rotation of the transport motor 102 to the discharge roller 62 via the first transmission unit 74. On the other hand, when the planetary gear 152 meshes with the rotating body 112, the reverse rotation of the transport motor 102 is transmitted from the planetary gear 152 to the rotating body 112. Thereby, the rotating body 112 rotates in the circumferential direction 155. Then, the surface 126B of the convex portion 126 comes into contact with the surface 118B of the convex portion 118 of the rotating body 111 and presses the surface 118B. Thereby, the rotating body 111 rotates in the circumferential direction 155 integrally with the rotating body 112. As a result, the shaft 62A of the discharge roller 62 that rotates integrally with the rotating body 111 also rotates in the circumferential direction 155. That is, the discharge roller 62 rotates in the reverse direction (see FIG. 6B).

  In the present embodiment, when the torque T1 is applied to the rotating body 112, the gear 154 interrupts the torque transmitted between the rotating bodies 111 and 112. However, the gear 154 is not necessarily interrupted. That is, when the torque T1 is applied to the rotating body 112, the gear 154 may make the torque transmitted between the rotating bodies 111 and 112 less than the torque T2 and greater than zero.

  In the present embodiment, the gear 154 corresponds to the torque limiter of the present invention. However, the torque limiter of the present invention only needs to be provided between the planetary gear 152 and the discharge roller 62 in the transmission path of the rotation of the transport motor 102 in the second transmission section 149, and the gear itself meshing with the planetary gear is used. It does not need to be provided. For example, when a gear train (not shown) is provided between the planetary gear 152 and the gear 154 in the transmission path, the torque limiter of the present invention is any of the gears constituting the gear train. May be.

  In the present embodiment, the rotating body 112 is an example of a first rotating body, and the rotating body 111 is an example of a second rotating body. However, contrary to the present embodiment, the rotating body 111 may be an example of a first rotating body, and the rotating body 112 may be an example of a second rotating body. In this case, the urging member 113 urges the rotating body 111 toward the rotating body 112. However, in this case, it is preferable that the rotating body 111 is not attached to the shaft 62A because a gear is provided between the rotating body 111 and the shaft 62A of the discharge roller 62.

  Further, when the torque limiter of the present invention applies a torque T1 to the rotating body 111 or the rotating body 112 that is larger than the torque T2 required for the discharge roller 62 to rotate, the rotating body 111, 112 What is necessary is just to have the function which makes the torque which transfers between less than the torque T2. That is, the specific configuration of the torque limiter of the present invention is not limited to the above-described configuration, and may be another known configuration provided that the torque limiter has the function.

[Control unit 130]
As shown in FIG. 8, the control unit 130 includes a CPU 131, a ROM 132, a RAM 133, an EEPROM 134, and an ASIC 135, which are connected by an internal bus 137. The ROM 132 stores programs and the like for the CPU 131 to control various operations. The RAM 133 is used as a storage area for temporarily recording data, signals, and the like used when the CPU 131 executes the program, or as a work area for data processing. The EEPROM 134 stores settings, flags, and the like that should be retained even after the power is turned off.

  The transport motor 102 and the carriage motor 103 are connected to the ASIC 135. The ASIC 135 generates a drive signal for rotating each motor, and controls each motor based on the drive signal. Each motor rotates forward or reverse according to a drive signal from the ASIC 135. For example, the control unit 130 controls the driving of the transport motor 102 to drive each roller. Further, the control unit 130 controls the driving of the carriage motor 103 to reciprocate the carriage 23. Further, the control unit 130 controls the recording head 39 to eject ink from the nozzles 40.

  The ASIC 135 is connected to the first sensor 120, the rotary encoder 121, and the second sensor 122. The control unit 130 detects the presence of the sheet 12 at the position where each sensor is arranged, based on the detection signals output from the first sensor 120 and the second sensor 122. Further, control unit 130 detects the position of sheet 12 based on the detection signal output from first sensor 120 and the pulse signal output from rotary encoder 121.

[Image recording process]
With reference to FIG. 9, an image recording process according to the present embodiment will be described. This image recording process is executed by the CPU 131 of the control unit 130. Note that each of the following processes may be executed by the CPU 131 reading and executing a program stored in the ROM 132, or may be realized by a hardware circuit mounted on the control unit 130.

  The control unit 130 executes an image recording process in response to a recording instruction for recording an image on both sides of a sheet from a user. Although the acquisition destination of the recording instruction is not particularly limited, for example, the recording instruction may be acquired through the operation unit 17 (see FIG. 1) provided in the multifunction peripheral 10, or may be acquired from an external device through a communication network. The control unit 130 records an image on the sheet 12 by controlling the operations of the rollers, the carriage 23, and the recording head 39 according to the acquired recording instruction.

  First, the control unit 130 switches the switching mechanism 170 to the first state (S11). Specifically, the control unit 130 causes the switching lever 176 to abut on the first stopper 180 by moving the carriage 23 along the right direction 8 and the left direction 9. Thereby, the switching gear 171 is moved, and the switching gear 171 and the receiving gear 172A are meshed. However, when the switching mechanism 170 is already in the first state, the control unit 130 executes the processing after step S12 without executing step S11.

  Next, the control unit 130 performs a front surface feeding process on the sheet 12 (S12). The front surface feeding process is a process for causing the leading end (the downstream end in the first transport direction 16 </ b> A) of the paper 12 supported by the feed tray 20 to reach the transport unit 54. Specifically, the control unit 130 rotates the feed roller 25 by rotating the transport motor 102 in the reverse direction.

  Next, the control unit 130 performs a front surface recording process on the paper 12 (S13). The front surface recording process is a process of recording an image on the surface of the paper 12. More specifically, in step S13, the control unit 130 alternately and repeatedly executes the transport process and the ejection process. The transport process is a process of transporting the sheet 12 that has reached the transport unit 54 to at least one of the transport unit 54, the discharge unit 55, and the reversing unit 56 by a predetermined line feed width in the first transport direction 16A. The ejection process is a process of causing the recording head 39 to eject ink to the sheet 12 conveyed by a predetermined line feed width.

  Specifically, the control unit 130 rotates the rollers 60, 62, and 45 forward by rotating the transport motor 102 in the transport process. The forward rotation of the transport motor 102 is transmitted from the transport roller 60 to the discharge roller 62 and the reversing roller 45 via the first transmission unit 74. In the ejection process, the control unit 130 drives the carriage motor 103 to move the carriage 23 along the right direction 8 and the left direction 9 and causes the recording head 39 to eject ink at a predetermined timing.

  Next, the control unit 130 executes a front surface discharge process on the sheet 12 (S14). In the front side sheet discharging process, the rear end (upstream end in the first conveying direction 16A) of the sheet 12 having the image recorded on the front side is branched to at least one of the conveying unit 54, the discharging unit 55, and the reversing unit 56 at the branch position 66A. Is a process of transporting the paper 12 in the first transport direction 16A to a position where the paper 12 is reached. Specifically, the control unit 130 causes the rollers 60, 62, and 45 to rotate forward by rotating the transport motor 102 forward. At this time, the flap 49 rotates from the reversing position to the discharge position by being lifted by the sheet 12 conveyed in the first conveyance direction 16A, and then, when the rear end of the sheet 12 reaches the branch position 66A, due to its own weight. It rotates from the discharge position to the reverse position. As a result, the rear end of the sheet 12 faces the second transport path 66.

  Next, the controller 130 switches the switching mechanism 170 from the first state to the second state (S15). Specifically, the control unit 130 causes the switching lever 176 to abut on the second stopper 181 by moving the carriage 23 in the right direction 8. Thereby, the switching gear 171 is moved, and the switching gear 171 and the receiving gear 172B are meshed.

  Next, the control unit 130 performs a back surface feeding process (S16). The back sheet feeding process is a process of turning over the sheet 12 on which an image is recorded on the front surface and causing the sheet 12 to reach the transport unit 54 again. Specifically, the control unit 130 causes the reverse rotation of the reversing roller 45 and the normal rotation of the re-transport roller 68 by reversing the transport motor 102. As a result, the paper 12 enters the second conveyance path 66 from the branch position 66A with the upstream end in the first conveyance direction 16A as the leading end, and reaches the conveyance section 54 through the junction position 66B. The reverse rotation of the transport motor 102 is transmitted from the transport roller 60 to the discharge roller 62 and the reversing roller 45 via the second transmission section 149, and transmitted from the transport roller 60 to the re-transport roller 68 via the fourth transmission section 140. Is done.

  Next, the control unit 130 performs a back surface recording process on the sheet 12 (S17). The backside recording process is a process for recording an image on the backside of the paper 12. The backside recording process is a process in which the transport process and the ejection process are alternately repeated, similarly to the frontside recording process.

  The control unit 130 rotates the transport motor 102 forward in the transport process of the backside recording process. Thus, the forward rotation of the transport motor 102 is transmitted from the transport roller 60 to the discharge roller 62 and the reversing roller 45 via the first transmission unit 74, and causes the rollers 60, 62, and 45 to rotate forward. That is, the control unit 130 switches the rotation of the transport motor 102, which has been reversed in the backside sheet feeding process, to the normal rotation in the transporting process. The switching of the rotation of the transport motor 102 is performed before the paper 12 reaches the transport unit 54 through the junction position 66B. Thus, when the paper 12 reaches the transport unit 54, the transport unit 54 can transport the paper 12 in the first transport direction 16A. Further, even if the transport motor 102 switches from reverse rotation to normal rotation, the re-transport roller 68 continues to rotate forward, so that the transport of the paper 12 along the second transport path 66 is performed normally.

  When the transport motor 102 is switched from the reverse rotation to the forward rotation, the planetary gear 152 is separated from the gear 154 by transmitting the forward rotation of the transport motor 102 to the second transmission unit 149. When the transport motor 102 is switched from the reverse rotation to the forward rotation, the forward rotation of the transport motor 102 is transmitted from the transport roller 60 to the discharge roller 62 via the first transmission unit 74. At this time, the timing at which the forward rotation of the transport motor 102 can be transmitted from the transport roller 60 to the discharge roller 62 via the first transmission unit 74 is earlier than the timing at which the planetary gear 152 is separated from the gear 154. If this occurs, the gear 154 functions as a torque limiter. Accordingly, it is possible to prevent the gear 154 to which the forward rotation of the transport motor 62 has been transmitted via the first transmission unit 74 and the discharge roller 62 from obstructing separation of the planetary gear 152 from the gear 154.

  Next, the control unit 130 executes a backside discharge process (S18). The back side paper discharge process conveys the sheet 12 to the discharge unit 55 and the reversing unit 56 in the first conveying direction 16A until the sheet 12 passes through the reversing unit 56 (that is, until the sheet 12 is discharged to the discharge tray 21). This is the process to make it. Specifically, the control unit 130 causes the rollers 60, 62, and 45 to rotate forward by rotating the transport motor 102 forward.

[Effects of the present embodiment]
When the rotation transmitted from the conveyance motor 102 to the conveyance roller 60 changes from the reverse rotation to the normal rotation, the rotation of the conveyance motor 102 can be temporarily transmitted to the gear 154 via the first transmission unit 74 and the discharge roller 62. Is earlier than the timing at which the planetary gear 152 separates from the gear 154, the gear 154 is rotated by the forward rotation of the transport motor 102 in a state of meshing with the planetary gear 152. As a result, the planet gear 152 cannot be separated from the gear 154.

  At this time, according to the above embodiment, when the torque T2 is applied to the rotating body 112, the torque transmitted between the rotating bodies 111 and 112 decreases. Accordingly, the force that causes the planetary gear 152 to separate from the gear 154 by the rotation of the sun gear 151 in the first rotation direction 105 to which the forward rotation of the transport motor 102 has been transmitted via the second transmission unit 149 is applied to the first transmission. The forward rotation of the conveyance motor 102 transmitted via the portion 74 and the discharge roller 62 causes the gear 154 to be larger than the force for maintaining the mesh with the planetary gear 152. Then, the planet gear 152 is separated from the gear 154. As a result, locking of the transport motor 102 can be prevented.

  Further, according to the above-described embodiment, the state in which the torque transmitted between the rotating bodies 111 and 112 is less than the torque T2 is limited to the time when the rotating body 111 rotates less than one round by the torque of the torque T2. I have. Therefore, when the rotating body 111 rotates less than one round, the torque transmitted between the rotating bodies 111 and 112 is at least the torque T2. Thus, the state in which the reverse rotation of the transport motor 102 can be transmitted from the transport roller 60 to the discharge roller 62 via the second transmission unit 149 is possible. At this time, since the planet gear 152 is already separated from the gear 154, an excessive torque such as the torque T2 is not applied to the rotating body 112. Therefore, the transport motor 102 does not lock.

  Further, according to the above embodiment, the torque transmitted between the rotating bodies 111 and 112 in the set section is zero. Therefore, the difference between the force for separating the planet gear 152 from the gear 154 and the force for maintaining the gear 154 in mesh with the planet gear 152 can be increased. As a result, the planetary gear 152 can be more reliably separated from the gear 154.

  According to the above-described embodiment, the gear 154 includes the rotating body 111 having the convex portion 118 formed thereon, the rotating body 112 having the convex portion 126 formed therein, and the urging member 113. Therefore, a torque limiter having the above-described function can be realized with a simple configuration.

  Further, according to the above embodiment, since the convex portions 118 and 126 have the inclined surfaces 118A, 118B, 126A and 126B, the convex portion 118 pushes the convex portion 126 in the circumferential direction 156 so that the rotating body 112 is pressed. In the right direction 8 can be smoothly executed.

  Further, according to the above embodiment, since the plurality of protrusions 118 and 126 are provided, the rotation amount of the rotating body 111 corresponding to the set section can be reduced. Thus, the time from when the torque T1 is applied to the rotating body 112 to when the state where the reverse rotation of the transport motor 102 can be transmitted from the transport roller 60 to the discharge roller 62 via the second transmission unit 149 is reduced. be able to.

  Further, according to the above-described embodiment, both the protrusions 118 and 126 are provided at equal intervals along the circumferential direction 155 and 156, and the same number of the protrusions 118 and 126 are provided. Thereby, the bias in the circumferential directions 155 and 156 of the torque transmitted between the rotating bodies 111 and 112 can be reduced.

  Further, according to the above-described embodiment, the provision of the one-way clutch 83 allows the first transmission section 74 to be realized with a simple configuration.

  Further, according to the above-described embodiment, by setting the switching mechanism 170 to the first state, the discharge roller 62 can be stopped while rotating the transport roller 60. For example, the discharge roller 62 can be stopped while rotating the transport roller 60 in a direction that transports the sheet 12 in a direction opposite to the first transport direction 16A. Thereby, the sheet 12 conveyed toward the conveying roller 60 abuts on the conveying roller 60 rotating in a direction for conveying the sheet 12 in a direction opposite to the first conveying direction 16 </ b> A. Can be corrected. Further, at this time, even if the paper 12 preceding the paper 12 is in contact with the discharge roller 62, the discharge roller 62 is stopped, so that the preceding paper 12 is conveyed by the discharge roller 62. Never.

  Further, according to the above-described embodiment, the switching mechanism 170 is set to the first state, and the reverse rotation of the transport motor 102 is transmitted to the transport roller 60, so that the sheet 12 supported by the transport tray 20 is transported to the transport roller 25. Can be fed toward the transport roller 60.

  Further, according to the above embodiment, the switching mechanism 170 is set to the second state, and the rotation of the transport motor 102 is transmitted from the transport roller 60 to the re-transport roller 68 via the fourth transmission unit 140, whereby the second transport is performed. The paper 12 guided to the path 66 can be transported along the second transport path 66 by the re-transport roller 68. Further, according to the state of the switching mechanism 170, the feeding of the paper 12 by the feed roller 25 and the transport of the paper 12 along the second transport path 66 by the re-transport roller 68 can be executed separately.

  According to the above-described embodiment, a portion from the discharge roller 62 to the reversing roller 45 in the drive transmission path of the first transmission unit 74 and the second transmission unit 149 can be shared. Thereby, the space occupied by the first transmission unit 74 and the second transmission unit 149 can be reduced.

  Further, according to the above embodiment, the first transmission unit 74 is provided on the left side of the first transport path 65, and the second transmission unit 149 is provided on the right side of the first transport path 65. I have. Accordingly, the first transmission unit 74 and the second transmission unit 149 do not interfere with each other, and thus the configuration of each of the transmission units 74 and 149 can be simplified.

[Modification]
In the above embodiment, each of the rollers 60, 62, 45 to which the forward rotation of the transport motor 102 is transmitted via the first transmission unit 74 rotates forward, and the reverse rotation of the transport motor 102 via the second transmission unit 149. Although the transmitted rollers 60, 62, and 45 are reversed, the rotation direction of each roller 60, 62, and 45 is not limited to the direction of the above-described embodiment. For example, each of the rollers 60, 62, and 45 is transmitted when the forward rotation of the transport motor 102 is transmitted through the first transmission unit 74 and when the reverse rotation of the transport motor 102 is transmitted through the second transmission unit 149. In either case, the rotation may be in the same direction.

  Further, in the above-described embodiment, the driving unit of the present invention is the transport roller 60, but is not limited to the transport roller 60. For example, the drive unit of the present invention may be a pump (not shown) driven when sucking the ink in the nozzle 40. The pump is arranged in a tube (not shown) connected to the nozzle when the ink in the nozzle 40 is sucked. One end of the tube is connected to the nozzle 40, and the other end of the tube is connected to a waste ink tank (not shown). When the pump is driven, the tube is handled. Thereby, the ink in the nozzle 40 is sucked by the tube and circulated to the waste ink tank. When the driving unit of the present invention is a pump, the rotation of the transport motor 102 is transmitted from the pump to the discharge roller 62 by a gear or the like provided on the pump.

  The forward rotation and the reverse rotation transmitted from the transport motor 102 to each of the rollers 25, 60, 62, 45, and 68 may be opposite to those in the above-described embodiment. For example, in the above-described embodiment, the rollers 60, 62, and 45 to which the forward rotation of the transport motor 102 is transmitted via the first transmission unit 74 rotate forward, and the rotation of the transport motor 102 via the second transmission unit 149. Each of the rollers 60, 62, and 45 to which the reverse rotation was transmitted has reversed. However, contrary to the above-described embodiment, the rollers 60, 62, and 45 to which the reverse rotation of the transport motor 102 has been transmitted via the first transmission unit 74 rotate forward, and the transport motor 102 via the second transmission unit 149. The rollers 60, 62, and 45 to which the forward rotation of 102 has been transmitted may be reversed.

  The second transport path 66 is shown in FIG. 2 on the condition that the paper 12 on which the image is recorded by the recording unit 24 can reach the recording unit 24 again with the front and back turned over. The configuration may be different from the one described above. For example, the branch position 66A may be located upstream of the recording unit 24 in the first transport direction 16A, and the junction position 66B may be located upstream of the branch position 66A in the first transport direction 16A.

  Further, in the image recording process in the above embodiment, the gear 154 may function as a torque limiter during the conveyance process in the back surface recording process when performing image recording on both sides of the paper 12. However, the gear 154 can function as a torque limiter not only in the conveyance process in the backside recording process but also in any case when the conveyance motor 102 is switched from normal rotation to reverse rotation or from reverse rotation to normal rotation. It may be time.

  For example, the gear 154 functions as a torque limiter when the rotation of the transport motor 102 is switched when the multifunction peripheral 10 has a function of recording an image on the surface of a plate-shaped recording medium such as a CD or DVD. May be. In this case, after the recording medium is inserted from the opening 13 in the direction opposite to the first transport direction 16A, the image is recorded while being transported in the first transport direction 16A, and then discharged through the opening 13. The transport motor 102 is rotated backward when the recording medium is inserted in the direction opposite to the first transport direction 16A, and is rotated forward when the recording medium is transported in the first transport direction 16A. That is, when the transport direction of the recording medium is switched, the transport motor 102 is switched from reverse rotation to normal rotation. At this time, the gear 154 may function as a torque limiter.

10 Multifunction machine 24 Recording unit 60 Transport roller (drive unit, second roller)
62... Discharge roller (first roller)
65 1st conveyance path 74 1st transmission part (1st drive transmission mechanism)
102—Transport motor (motor)
105 first rotation direction 106 second rotation direction 111 rotating body 112 rotating body 149 second transmission unit (second drive transmission mechanism)
151 ... sun gear 152 ... planetary gear 153 ... arm 154 ... gear (transmission gear, torque limiter)

Claims (17)

A motor that rotates forward and reverse,
At least one of forward rotation or reverse rotation of the motor, a driving unit that is driven by being transmitted from the motor,
A first roller provided in a first conveyance path through which the sheet is conveyed,
A first drive transmission mechanism that transmits one of forward rotation or reverse rotation of the motor from the drive unit to the first roller, and that does not transmit the other of forward rotation or reverse rotation of the motor from the drive unit to the first roller;
A second drive transmission mechanism that transmits the other of the forward rotation or the reverse rotation of the motor from the drive unit to the first roller and does not transmit one of the forward rotation or the reverse rotation of the motor from the drive unit to the first roller; With
The second drive transmission mechanism includes:
One of the forward rotation and the reverse rotation of the motor is transmitted from the driving unit, and the motor rotates in a first rotation direction. The other of the forward rotation and the reverse rotation of the motor is transmitted from the driving unit, and the rotation direction is opposite to the first rotation direction. A sun gear rotating in a second rotation direction of
An arm rotatably supported by the sun gear,
A planetary gear that is rotatably supported by the arm while meshed with the sun gear, and is capable of revolving around the sun gear;
A transmission gear capable of meshing with the planetary gear and transmitting the rotation of the motor transmitted from the planetary gear to the first roller;
A torque limiter provided between the planetary gear and the first roller in a transmission path of the rotation of the motor, and having a first rotating body and a second rotating body capable of mutually transmitting the rotation of the motor; Prepare
The planet gear revolves in a direction away from the transmission gear by rotation of the sun gear in the first rotation direction, and revolves in a direction meshing with the transmission gear by rotation of the sun gear in the second rotation direction. ,
When the torque limiter receives a second amount of torque larger than a first amount of torque required for the first roller to rotate, the first rotator or the second rotator applies a torque during a set section. The torque transmitted between the first rotator and the second rotator is maintained at less than the first amount , and after the set section, the torque transmitted between the first rotator and the second rotator is transmitted. Torque that is equal to or greater than the first amount ,
The transport device in which the set section is a section in which the first rotating body or the second rotating body rotates a predetermined rotation amount of less than one rotation.   When the torque of the second amount is applied to the first rotating body or the second rotating body, the torque limiter transmits the torque transmitted between the first rotating body and the second rotating body during the set section. The transfer device according to claim 1, wherein the transfer device is blocked. The torque limiter further includes an urging member for urging the first rotating body toward the second rotating body,
The first rotator rotates coaxially with the second rotator, and includes a first protrusion protruding toward the second rotator in an axial direction,
The second rotating body includes a second convex portion protruding toward the first rotating body in the axial direction,
The first convex portion can abut on the second convex portion in a circumferential direction in a state where the first rotating body is urged by the urging member,
The first rotating body resists the urging force of the urging member when one of the first convex portion or the second convex portion pushes the other with the second amount or more of torque along the circumferential direction. The transport device according to claim 2, wherein the transport device moves in a direction away from the second rotating body along the axial direction.   A motor that rotates forward and reverse,
  At least one of forward rotation or reverse rotation of the motor, a driving unit that is driven by being transmitted from the motor,
  A first roller provided in a first conveyance path through which the sheet is conveyed,
  A first drive transmission mechanism that transmits one of forward rotation or reverse rotation of the motor from the drive unit to the first roller, and that does not transmit the other of forward rotation or reverse rotation of the motor from the drive unit to the first roller;
  A second drive transmission mechanism that transmits the other of the forward rotation or the reverse rotation of the motor from the drive unit to the first roller and does not transmit one of the forward rotation or the reverse rotation of the motor from the drive unit to the first roller; With
  The second drive transmission mechanism includes:
  One of the forward rotation and the reverse rotation of the motor is transmitted from the driving unit, and the motor rotates in a first rotation direction. The other of the forward rotation and the reverse rotation of the motor is transmitted from the driving unit, and the rotation direction is opposite to the first rotation direction. A sun gear rotating in a second rotation direction of
  An arm rotatably supported by the sun gear,
  A planetary gear that is rotatably supported by the arm while meshed with the sun gear, and is capable of revolving around the sun gear;
  A transmission gear capable of meshing with the planetary gear and transmitting the rotation of the motor transmitted from the planetary gear to the first roller;
  A first rotating body and a second rotating body that are provided between the planetary gear and the first roller in a transmission path of the rotation of the motor and that can mutually transmit the rotation of the motor; and the first rotating body. A torque limiter having an urging member for urging the second rotating body toward the second rotating body.
  The planet gear revolves in a direction away from the transmission gear by rotation of the sun gear in the first rotation direction, and revolves in a direction meshing with the transmission gear by rotation of the sun gear in the second rotation direction. ,
  When the torque limiter receives a second amount of torque larger than a first amount of torque required for the first roller to rotate, the first rotator or the second rotator applies a torque during a set section. Interrupting the torque transmitted between the first rotating body and the second rotating body,
  The set section is a section in which the first rotating body or the second rotating body rotates a predetermined rotation amount of less than one rotation,
  The first rotator rotates coaxially with the second rotator, and includes a first protrusion protruding toward the second rotator in an axial direction,
  The second rotating body includes a second convex portion protruding toward the first rotating body in the axial direction,
  The first convex portion can abut on the second convex portion in a circumferential direction in a state where the first rotating body is urged by the urging member,
  The first rotating body resists the urging force of the urging member when one of the first convex portion or the second convex portion pushes the other with the second amount or more of torque along the circumferential direction. A transfer device that moves in a direction away from the second rotating body along the axial direction. The surface of at least one of the first convex portion and the second convex portion facing in the circumferential direction is such that the protruding tip of the first convex portion or the second convex portion having the surface is larger than the protruding base end. There conveying device according to claim 3 or 4 is inclined so as to be positioned downstream in the direction to be pressed along the circumferential direction. The transport device according to any one of claims 3 to 5, wherein one of the first protrusion and the second protrusion is provided at equal intervals along the circumferential direction. The other of the first projections or the second projections, at regular intervals along the circumferential direction, according to claim 6 provided the same number one and the first protrusion or the second protrusion Transport device. The first drive transmission mechanism rotates integrally with the first roller by transmitting one of the forward rotation and the reverse rotation of the motor, and transmits the second rotation by transmitting the other of the forward rotation and the reverse rotation of the motor. conveying device according to any one of claims 1 to 7 comprising a one-way clutch rotates idly with respect to first roller. The drive unit transmits one of forward rotation or reverse rotation of the motor from the motor, rotates in a direction in which the sheet is transported in the transport direction, and transmits the other of forward rotation or reverse rotation of the motor from the motor. A second roller that rotates in a direction to convey the sheet in a direction opposite to the conveyance direction,
The first roller receives one of forward rotation and reverse rotation of the motor from the second roller via the first drive transmission mechanism, and rotates in a direction in which the sheet is transported in the transport direction. The other of normal rotation and reverse rotation of the motor is transmitted from the roller via the second drive transmission mechanism, and rotates in a direction in which the sheet is transported in a direction opposite to the transport direction.
The second roller, the conveying device according to any one of the first conveying path in the first claim is provided upstream of the conveying direction than the roller to claim 1 to 8. The first state in which the transmission of the rotation of the motor from the second roller to the first roller via the second drive transmission mechanism is interrupted, and the state from the second roller via the second drive transmission mechanism. The transport device according to claim 9 , further comprising a switching mechanism capable of switching a state to a second state capable of transmitting rotation of the motor to the first roller. A tray on which the sheets are supported,
A feed roller that feeds the sheet supported by the tray toward the second roller in the transport direction;
A third drive transmission mechanism that transmits the other of forward rotation or reverse rotation of the motor from the second roller to the feed roller and does not transmit one of forward rotation or reverse rotation of the motor from the second roller to the feed roller; And further comprising
The switching mechanism enables the rotation of the motor to be transmitted from the second roller to the feed roller via the third drive transmission mechanism in the first state, and the third drive transmission in the second state. The transport device according to claim 10 , wherein transmission of rotation of the motor from the second roller to the feed roller via a mechanism is interrupted. A third roller provided on a second transport path connected to the first transport path,
And a fourth drive transmission mechanism for transmitting the forward rotation and the reverse rotation of the motor from the second roller to the third roller as rotation for rotating the sheet guided to the second transport path in a direction in which the sheet can be transported. In addition,
The switching mechanism interrupts transmission of rotation of the motor from the second roller to the third roller via the fourth drive transmission mechanism in the first state, and transmits the fourth drive transmission in the second state. conveying device according to the second roller through a mechanism in claim 10 or 11 to allow transmission of rotation of the motor to the third roller. A fourth roller provided further downstream in the transport direction than the first roller in the first transport path;
The second transport path is provided at a first connection position between the first roller and the fourth roller and at a second connection position upstream of the second roller in the transport direction. Connected to
The first drive transmission mechanism transmits one of forward rotation and reverse rotation of the motor from the second roller to the fourth roller via the first roller,
The transport device according to claim 12 , wherein the second drive transmission mechanism transmits the other of the forward rotation and the reverse rotation of the motor from the second roller to the fourth roller via the first roller. The first drive transmission mechanism includes:
A first pulley that rotates in conjunction with the rotation of the second roller,
A second pulley for rotating the first roller in association with the second pulley,
A third pulley that rotates in conjunction with the rotation of the second pulley,
A fourth pulley that rotates the fourth roller in conjunction with the fourth pulley,
A first belt wound around the first pulley and the second pulley,
A second belt wound around the third pulley and the fourth pulley,
The second drive transmission mechanism includes:
The transport device according to claim 13 , further comprising the third pulley, the fourth pulley, and the second belt. The first drive transmission mechanism transmits the rotation of the motor to the first roller from one end in the axial direction of the first roller,
The second drive transmission mechanism, conveying device according to any one of claims 1 to 14 for transmitting rotation from the other end of the motor to the first roller in the axial direction of the first roller. A transport device according to any one of claims 1 to 15 ,
An image recording apparatus, comprising: a recording unit that is provided in the first transport path and records an image on a sheet. The image recording apparatus according to claim 16 , wherein the recording unit is provided upstream of the first roller in a sheet conveying direction.

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