Drive transmission mechanism

Abstract

To provide a drive transmission mechanism not requiring rotation of a gear for connection of the gear.SOLUTION: The second drive transmission mechanism 301 includes a pair of rear arms 322 rotatably supported by the first shaft 311 and the second shaft 315, and a pair of front arms 323 rotatably supported by the second shaft 315 and the third shaft 317. The pair of rear arms 322 and the pair of front arms 323 are pivotable relative to the second shaft 315 independently of each other. As a result, when the middle guide member 104 rotates with respect to the inner frame 51, the pair of rear arms 322 and the pair of front arms 323 rotate and the second gear 314 moves while maintaining the state of meshing with the first gear 313 and the third gear 316. Therefore, after the middle guide member 104 is rotated with respect to the inner frame 51, an operation for connecting each gear is not required.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a drive transmission mechanism that transmits the driving force of a motor. [Background technology]

[0002] One known example of a drive transmission mechanism for transmitting the driving force of a motor is the drive transmission mechanism described in Patent Document 1. The drive transmission mechanism described in Patent Document 1 includes a sun gear rotatably supported on a frame and driven by the driving force of a drive motor, a planetary gear that meshes with the sun gear, and a second transmission gear, a third transmission gear, a fourth transmission gear, and a feed roller, each rotatably supported on an arm. The planetary gear is supported so that it can mesh with the second transmission gear as the sun gear rotates. When the sun gear rotates in a first rotational direction, the planetary gear revolves around the sun gear in the first rotational direction and meshes with the second transmission gear. This allows the driving force from the sun gear to be transmitted to the feed roller via the planetary gear, the second transmission gear, the third transmission gear, and the fourth transmission gear. On the other hand, when the sun gear rotates in a second rotational direction, the planetary gear revolves around the sun gear in the second rotational direction and moves away from the second transmission gear. This prevents the driving force from the sun gear from being transmitted to the feed roller. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-201435 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above drive transmission mechanism, after the second link member changes position from the eighth position to the seventh position due to the installation of the paper feed cassette, the planetary gear needs to revolve a predetermined amount around the sun gear in order to connect to the second transmission gear when transmitting the driving force of the motor to the feed roller.

[0005] An object of the present disclosure is to provide a drive transmission mechanism that does not require gear rotation for gear engagement. [Means for solving the problem]

[0006] (1) The present disclosure relates to a drive transmission mechanism. The drive transmission mechanism includes a first unit, a second unit rotatably attached to the first unit, a first drive transmission element that transmits drive force, a first gear driven by the drive force from the first drive transmission element, a first shaft to which the first gear is connected, extending parallel to a rotation axis of the second unit and attached to the first unit, a second gear that meshes with the first gear, a second shaft to which the second gear is connected, extending parallel to the first shaft, a third gear that meshes with the second gear, a third shaft to which the third gear is connected, extending parallel to the second shaft and attached to the second unit, a first arm rotatably supported on the first shaft and the second shaft, and a second arm rotatably supported on the second shaft and the third shaft. The first arm and the second arm are rotatable relative to the second shaft independently of each other.

[0007] When the second unit rotates relative to the first unit, the distance between the first gear and the third gear changes. The first gear and the second gear are connected via the first arm, so they maintain a meshed state. The second gear and the third gear are connected via the second arm, so they maintain a meshed state. Therefore, even if the distance between the first gear and the third gear changes, the first arm and the second arm rotate, and the second gear moves while maintaining a meshed state with the first gear and the third gear. Therefore, there is no need for an operation to connect the gears after the second unit rotates relative to the first unit.

[0008] (2) The first gear may rotate integrally with the first shaft. The first shaft may be coupled to the first drive transmission element and rotated by rotation of the first drive transmission element.

[0009] This saves space compared to when the first drive transmission element and the first gear are supported on separate shafts.

[0010] (3) The first shaft does not have to be supported by the first unit via a bearing.

[0011] Since errors in assembly of the first unit and the second unit do not affect the first shaft, resistance to rotation of the first shaft is unlikely to occur.

[0012] (4) The first unit may have an insertion hole through which the first shaft is inserted.

[0013] The first shaft is prevented from coming off the first unit.

[0014] (5) The second unit may be rotatable between a first position and a second position rotated downward from the first position. At least one of the first arm and the second arm may have a restricting portion that restricts a rotation range of the first arm relative to the second arm.

[0015] When the first arm rotates freely relative to the second arm, the position of the first shaft also changes freely, which may cause it to come into contact with the inner surface that defines the insertion hole of the first unit. However, the restricting portion restricts the rotation range of the first arm, thereby preventing the first shaft from coming into contact with the inner surface of the through hole.

[0016] (6) The drive transmission mechanism may further include a second drive transmission element that transmits a drive force, and a fourth shaft that is driven by the drive force from the second drive transmission element. The first drive transmission element may directly transmit the drive force from the fourth shaft to the first gear. The fourth shaft may be rotatably supported by the first unit via a bearing.

[0017] The fourth shaft is supported by the first unit and is therefore less likely to bend.

[0018] (7) The second shaft may have an axle portion inserted through a first connecting hole located in the first arm and a second connecting hole located in the second arm so as to be rotatable and movable in the axial direction, and a rotating portion extending from the axle portion in a direction intersecting the axial direction. The drive transmission mechanism may have a first abutment portion that abuts against the rotating portion to restrict a rotation range of the rotating portion, and a second abutment portion that abuts against the rotating portion to restrict a movement range of the rotating portion in the axial direction.

[0019] When the rotating portion of the second shaft abuts against the first abutment portion and the second abutment portion, the rotation range and axial movement range of the rotating portion are restricted, thereby preventing the shaft portion from coming off the first arm and the second arm.

[0020] (8) The pivoting portion may be movable to a position where it does not abut against the first contact portion and the second contact portion by being pivoted while being elastically deformed.

[0021] The user can rotate the rotating part while elastically deforming it, thereby removing the shaft part from the first arm and the second arm, which makes it easy to perform maintenance work on the drive transmission mechanism. [Effects of the Invention]

[0022] According to the present disclosure, gears do not need to be rotated to engage them. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a perspective view of the appearance of a multifunction peripheral 10. As shown in FIG. [Figure 2] FIG. 2 is a schematic diagram showing the internal configuration of the printer 11. As shown in FIG. [Figure 3] FIG. 3 is a perspective view of the appearance of the inner frame 51. As shown in FIG. [Figure 4] FIG. 4 is a top view showing the inside of the middle guide member 104 attached to the inner frame 51. As shown in FIG. [Figure 5]FIG. 5 is an enlarged view of the second drive transmission mechanism 301 and its surroundings in FIG. [Figure 6] FIG. 6 is a perspective view of the second drive transmission mechanism 301 and its surroundings, viewed obliquely from below. [Figure 7] FIG. 7 is a diagram showing a state in which the middle guide member 104 is located at the closed position relative to the inner frame 51. As shown in FIG. [Figure 8] FIG. 8 is a diagram showing a state in which the middle guide member 104 is located in the open position relative to the inner frame 51. As shown in FIG. [Figure 9] FIG. 9 shows a modified example of the second shaft 315 and the abutment piece 351. In FIG. [Figure 10] FIG. 10 is a schematic diagram showing a modified example of the second drive transmission mechanism 301. In FIG. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings as appropriate. Note that the embodiment described below is merely one example of the present disclosure, and it goes without saying that the embodiment of the present disclosure can be modified as appropriate without departing from the gist of the present disclosure. In the following description, the up-down direction is defined based on the state in which the multifunction device 10 is installed so that it can be used (the state in FIG. 1), the front-rear direction is defined with the side where the opening 13 is provided as the near side (front), and the left-right direction is defined when looking at the multifunction device 10 from the near side (front). The front-rear direction, the up-down direction, and the left-right direction are perpendicular to one another.

[0025] [Overall structure of the multifunction device 10] As shown in Fig. 1, the multifunction device 10 includes a printer 11 and a scanner 90. More specifically, the printer 11 and the scanner 90 are stacked one on top of the other to form the multifunction device 10. The multifunction device 10 has the function of recording images on both sides of recording paper 12 using an inkjet method. However, the multifunction device 10 may also record images on recording paper 12 using a method other than the inkjet method, for example, an electrophotographic method.

[0026] As shown in FIG. 1, the printer 11 has a housing 14 with an opening 13 formed in a front surface 75. The housing 14 has a first transport path 65 and a second transport path 71 (see FIG. 2) therein, which will be described later. The housing 14 has, for example, a frame for supporting each component of the printer 11 and an exterior cover that externally covers each component of the printer 11. Specifically, as shown in FIGS. 1 and 3, the housing 14 has an internal frame 51, a front cover 52, a rear cover 53, a right cover 54, and a left cover 55.

[0027] 3 and 4, the internal frame 51 includes a bottom frame 51A, four support columns 51B, and a shaft support portion 51E. The bottom frame 51A is a generally rectangular frame that is slightly longer in the left-right direction than in the front-to-rear direction. Specifically, the bottom frame 51A includes a right panel 511, a left panel 512, a front panel 513, and a rear panel 514.

[0028] The right plate 511 constitutes the right end portion of the bottom frame 51A. The right plate 511 has a generally flat plate shape that extends in the front-rear and left-right directions. The right plate 511 has a first through hole 201 into which a first shaft 311 (described later) is inserted. It is located on an upright plate 215 that rises from the upper surface of the right plate 511. The first through hole 201 is located slightly forward of the rear end portion of the right plate 511. The first through hole 201 faces in the left-right direction. The first through hole 201 is circular. The right plate 511 has a right protrusion 231 that protrudes leftward from its left end. The right protrusion 231 is located slightly forward of the first through hole 201 in the front-rear direction.

[0029] The left plate 512 constitutes the left end portion of the bottom frame 51A. The left plate 512 has a generally flat plate shape that extends in the front-rear and left-right directions. The left plate 512 has a left protrusion 232 that protrudes rightward from its right end. The left protrusion 232 is located slightly forward of the first through-hole 201 in the front-rear direction. The left protrusion 232 faces the right protrusion 231 in the left-right direction.

[0030] The front plate 513 forms the front end portion of the bottom frame 51A. The front plate 513 has a generally flat plate shape that extends in the front-to-back and left-to-right directions. The front plate 513 is located slightly rearward of the front ends of the right plate 511 and the left plate 512. The front plate 513 connects the right plate 511 and the left plate 512 in the left-to-right direction. The rear plate 514 forms the rear end portion of the bottom frame 51A. The rear plate 514 has a generally flat plate shape that extends in the front-to-back and left-to-right directions. The rear plate 514 connects the right plate 511 and the left plate 512 in the left-to-right direction.

[0031] The four support columns 51B are column-shaped and extend upward from the upper surface of the bottom frame 51A. The four support columns 51B are located near the four corners of the bottom frame 51A. In other words, the four support columns 51B are located at both front-rear ends of the right panel 511 and both front-rear ends of the left panel 512.

[0032] The shaft support portion 51E is located slightly forward of the rear plate 514. The shaft support portion 51E has a generally flat plate shape that extends in the front-to-rear and left-to-right directions. When viewed from the top-to-bottom direction, the shaft support portion 51E has a generally rectangular shape that is longer in the left-to-right direction than in the front-to-rear direction. The right end of the shaft support portion 51E is fixed to the left end of the right plate 511. The left end of the shaft support portion 51E is fixed to the right end of the left plate 512.

[0033] The shaft support portion 51E has a central cutout 251 that penetrates in the up-down direction. The central cutout 251 is located in the center of the shaft support portion 51E in the left-right direction. The central cutout 251 is a space formed by cutting out the shaft support portion 51E from the front end to the rear. The central cutout 251 has a rectangular shape that is long in the left-right direction when viewed from the up-down direction. The feed roller 25, which will be described later, is located in the central cutout 251.

[0034] The shaft support portion 51E has a right cutout portion 252 that penetrates in the up-down direction. The right cutout portion 252 is located at a distance to the right from the central cutout portion 251. The right cutout portion 252 is located at the right end portion of the shaft support portion 51E. The right cutout portion 252 is a space formed by cutting away from the front end of the shaft support portion 51E to the rear. The right cutout portion 252 has a rectangular shape that is long in the front-to-rear direction when viewed from the up-down direction. The right cutout portion 252 is smaller than the central cutout portion 251. A first gear 313, which will be described later, is located in the right cutout portion 252.

[0035] As shown in FIG. 5 , the shaft support portion 51E has a second through hole 202, a third through hole 203, and a fourth through hole 204, into which a first shaft 311 (described later) is inserted. Each of the through holes 202, 203, and 204 is circular. The second through hole 202 is adjacent to the right of the right cutout portion 252. The second through hole 202 faces the first through hole 201 in the left-right direction. The third through hole 203 is adjacent to the left of the right cutout portion 252. The third through hole 203 faces the second through hole 202 in the left-right direction. The fourth through hole 204 is located to the left of the third through hole 203 with a gap therebetween. The fourth through hole 204 faces the third through hole 203 in the left-right direction. Each of the through holes 201, 202, 203, and 204 is an example of an insertion hole.

[0036] As shown in FIG. 3, the internal frame 51 defines a storage space 51C in which the components of the printer 11 are housed. The storage space 51C is open in the front-to-rear, up-down, and left-to-right directions. That is, the internal frame 51 has a front opening 221, a rear opening 222, an upper opening 223, a lower opening 224, a right opening 225, and a left opening 226. The front opening 221 opens the storage space 51C forward. The rear opening 222 opens the storage space 51C rearward. The upper opening 223 opens the storage space 51C upward. The lower opening 224 opens the storage space 51C downward. The right opening 225 opens the storage space 51C to the right. The left opening 226 opens the storage space 51C to the left.

[0037] The inner frame 51 defines a tank accommodating space 51D in which an ink tank 112 that stores ink is accommodated. The tank accommodating space 51D is located at the right end of the inner frame 51, forward of the center in the front-to-rear direction. In other words, the tank accommodating space 51D is located above the top surface of the right plate 511, forward of the center in the front-to-rear direction of the right plate 511. Four bosses 17 protrude upward from the upper end of each support column 51B. The four bosses 17 fit into four fitting holes (not shown) provided at the lower end of the scanner 90. This allows the scanner 90 to be supported on the upper ends of the four support columns 51B. The upper opening 223 of the inner frame 51 is closed by the scanner 90 supported on the upper ends of the four support columns 51B. The inner frame 51 is an example of a first unit.

[0038] The scanner 90 performs a scanning operation to read an image recorded on the recording paper 12 and generate image data. Specifically, the scanner 90 includes a contact glass that supports an original, a reading sensor that reads the image recorded on the original supported on the contact glass, and an openable / closable FB cover 93. As shown in FIG. 1, a so-called ADF (short for Auto Document Feeder) is disposed on the top surface of the FB cover 93. The scanner 90 may also employ a so-called flatbed system.

[0039] The contact glass supports the document on its upper surface. The contact glass is made of a light-transmitting material. The contact glass is exposed to the outside of the scanner when the FB cover 93 is opened. On the other hand, the contact glass is covered by the FB cover 93 when the FB cover 93 is closed.

[0040] The reading sensor is disposed below the contact glass in a position facing the contact glass. The reading sensor is configured to be movable in the left-right direction between a standby position and a return position. During the process of moving from the standby position to the return position, the reading sensor reads an image recorded on a document supported on the upper surface of the contact glass.

[0041] The front cover 52 closes the front opening 221 of the internal frame 51. The front cover 52 constitutes the front surface 75 of the housing 14. The front cover 52 defines an opening 13 that communicates with the storage space 51C from the front. A tank cover 161 is provided to the right of the front cover 52. The tank cover 161 is attached to the front end of the internal frame 51 so as to be rotatable around a rotation axis that extends in the left-right direction. The tank cover 161 is rotatable between a closed position that closes the tank storage space 51D and an open position that opens the tank storage space 51D.

[0042] The rear cover 53 closes the rear opening 222 of the internal frame 51. The rear cover 53 constitutes the rear surface of the housing 14. The right cover 54 closes the right opening 225 of the internal frame 51. The right cover 54 constitutes the right surface of the housing 14. The left cover 55 closes the left opening 226 of the internal frame 51. The left cover 55 constitutes the left surface of the housing 14.

[0043] The components of the printer 11 are arranged below the scanner 90 in the storage space 51C of the internal frame 51. Specifically, the printer 11 includes a feed tray 20, a feed unit 16, a first transport path 65, and a second transport path 71.

[0044] [Feed Tray 20] As shown in Figures 1 and 2, the feed tray 20 can be inserted into and removed from the storage space 51C of the internal frame 51 through the opening 13. When the feed tray 20 is attached to the internal frame 51, the lower opening 224 of the internal frame 51 is closed. Recording paper 12 is supported on the feed tray 20. A discharge tray 21 is supported above the feed tray 20. Recording paper 12 on which an image has been recorded by a recording unit 24 (described later) is supported on the top surface of the discharge tray 21. The discharge tray 21 can be inserted into and removed from the housing 14 through the opening 13 together with the feed tray 20.

[0045] [Feeding section 16] As shown in FIG. 2, the feed unit 16 is located above the feed tray 20 when it is inserted into the housing 14. The feed unit 16 is supported by an intermediate guide member 104 disposed above the feed tray 20. The intermediate guide member 104 will be described later. The feed unit 16 includes a feed roller 25, a feed arm 26, a first drive transmission mechanism 27, and a support shaft 28. The feed roller 25 is supported at the tip end of the feed arm 26. The feed arm 26 is rotatable in the direction of arrow 29 around the support shaft 28 provided at the base end. The support shaft 28 is supported by the intermediate guide member 104, which will be described later. The feed roller 25 is capable of contacting and separating from the recording paper 12 supported by the feed tray 20.

[0046] The first drive transmission mechanism 27 transmits the forward rotation driving force of a conveyance motor (not shown) to the feed roller 25. On the other hand, the first drive transmission mechanism 27 does not transmit the reverse rotation driving force of the conveyance motor to the feed roller 25. Specifically, the first drive transmission mechanism 27 has a planetary gear 27A, a first transmission gear 27B, a second transmission gear 27C, and a third transmission gear 27D. The planetary gear 27A meshes with the support shaft 28 and the first transmission gear 27B. The planetary gear 27A is supported so as to mesh with or separate from the first transmission gear 27B depending on the rotation direction of the support shaft 28.

[0047] When the forward driving force of the conveyance motor rotates the support shaft 28 clockwise in FIG. 2, the planetary gear 27A revolves downward around the support shaft 28 and meshes with the first transmission gear 27B. At this time, the forward driving force of the conveyance motor is transmitted to the feed roller 25 via the first drive transmission mechanism 27. As a result, of the recording sheets 12 supported on the feed tray 20, the uppermost recording sheet 12 in contact with the feed roller 25 is fed to the first conveyance path 65.

[0048] 2, the planetary gear 27A revolves upward around the support shaft 28 and separates from the first transmission gear 27B. At this time, the reverse driving force of the conveyance motor is not transmitted to the feed roller 25.

[0049] [First conveying path 65] In the storage space 51C of the internal frame 51, a first conveying path 65 extends from the rear end of the feed tray 20. The first conveying path 65 includes a curved portion 33 and a straight portion 34. The curved portion 33 extends upward while curving from the rear end of the feed tray 20, and is connected to the straight portion 34 behind a pair of conveying rollers 59, which will be described later. The straight portion 34 extends in the front-rear direction from the connection position with the curved portion 33 to a pair of reversing rollers 45, which will be described later.

[0050] The curved portion 33 is defined by an outer guide member 18 and an inner guide member 19 that face each other at a predetermined distance. The straight portion 34 is defined behind the recording unit 24 by a conveying roller 60 and a pinch roller 61 that face each other. The straight portion 34 is defined at the position where the recording unit 24 is disposed by the recording unit 24 and a platen 42 that face each other at a predetermined distance. The straight portion 34 is defined ahead of the recording unit 24 by the platen 42, a discharge roller 62 and a spur roller 63 that face each other, a flap 49, and a reversing roller 67 and a spur roller 68 that face each other.

[0051] The recording paper 12 supported on the feed tray 20 is fed to the curved portion 33 by the feed roller 25, and is transported from the curved portion 33 to the straight portion 34 along the transport direction 15 indicated by the dashed arrow in Figure 2.

[0052] [Transport roller pair 59] A pair of conveying rollers 59 is disposed at the rear end of the straight section 34. The pair of conveying rollers 59 is located upstream of the recording section 24 in the conveying direction 15. The pair of conveying rollers 59 includes a conveying roller 60 disposed below the straight section 34 and a pinch roller 61 disposed above the straight section 34 facing the conveying roller 60. The conveying roller 60 is rotatable about a first rotation shaft 60A extending in the left-right direction. The first rotation shaft 60A is rotatably supported by the internal frame 51. The conveying roller 60 rotates forward (in the direction in which the recording paper 12 is conveyed in the conveying direction 15) when a forward driving force of the conveying motor is transmitted to it, and rotates reversely when a reverse driving force is transmitted to it. The pinch roller 61 can pinch the recording paper 12 on the first conveying path 65 between itself and the conveying roller 60. The pinch roller 61 rotates together with the rotation of the conveying roller 60.

[0053] [Platen 42] The platen 42 is located in front of the pair of conveying rollers 59. The platen 42 is located below the straight section 34. The platen 42 supports the recording paper 12 on the first conveying path 65. The platen 42 is rotatably supported on the first rotation shaft 60A. The platen 42 is held in the recording position by being supported from below by the middle guide member 104. When the middle guide member 104 rotates to the open position described below, the platen 42 rotates under its own weight, causing the front side to move downward to the release position. The top surface of the platen 42 in the release position is further downward from the straight section 34 than at the recording position.

[0054] [Records 24] The recording unit 24 is provided above the straight section 34. The recording unit 24 faces the platen 42 in the vertical direction. The recording unit 24 includes a carriage 40 and a recording head 38. The carriage 40 is supported by two guide rails arranged at a distance in the front-rear direction so as to be able to move back and forth in the left-right direction. Both left and right ends of the two guide rails are supported by an internal frame 51.

[0055] The recording head 38 is mounted on the carriage 40. Ink is supplied to the recording head 38 from an ink tank 112. Nozzles 39 are formed on the underside of the recording head 38. When the carriage 40 moves left and right, the recording head 38 ejects ink droplets from the nozzles 39 toward the platen 42. As a result, an image is recorded on the recording paper 12 that is transported along the straight section 34 in the transport direction 15 and supported by the platen 42.

[0056] [Discharge Roller Pair 44] A discharge roller pair 44 is disposed downstream of the platen 42 in the conveying direction 15 on the straight section 34. The discharge roller pair 44 includes a discharge roller 62 disposed below the straight section 34 and a spur roller 63 disposed above the straight section 34 facing the discharge roller 62. The discharge roller 62 is rotatable about a second rotation shaft 62A extending in the left-right direction. The second rotation shaft 62A is rotatably supported by the internal frame 51. The discharge roller 62 rotates forward when a forward driving force of the conveying motor is transmitted to it, and rotates reverse when a reverse driving force is transmitted to it. The spur roller 63 can clamp the recording paper 12 on the first conveying path 65 between itself and the discharge roller 62. The spur roller 63 rotates together with the rotation of the discharge roller 62.

[0057] [Flap 49] A flap 49 is disposed downstream of the discharge roller 62 in the conveying direction 15 on the straight section 34. The flap 49 is rotatably supported on a second rotation shaft 62A of the discharge roller 62. The flap 49 is rotatable about the second rotation shaft 62A between a first state and a second state. The first state is a state in which the first conveying path 65 is blocked. The second state (the state shown in FIG. 2) is a state in which the recording paper 12 conveyed in the conveying direction 15 passes through the straight section 34. The flap 49 is maintained in the first state by being urged upward by an urging member (not shown).

[0058] [45 pair of reversing rollers] The pair of reversing rollers 45 is disposed downstream of the flap 49 in the conveying direction 15 on the straight section 34. The pair of reversing rollers 45 includes a reversing roller 67 disposed below the straight section 34 and a spur roller 68 disposed above the straight section 34 facing the reversing roller 67. The reversing roller 67 is rotatable about a third rotation shaft 67A extending in the left-right direction. The reversing roller 67 is rotatably supported by the internal frame 51. The reversing roller 67 rotates forward when a forward driving force of the conveying motor is transmitted to it, and rotates reversely when a reverse driving force is transmitted to it. The spur roller 68 can clamp the recording paper 12 on the first conveying path 65 between itself and the reversing roller 67. The spur roller 68 rotates together with the rotation of the reversing roller 67.

[0059] When the rollers 60, 62, and 67 rotate forward while the recording paper 12 is sandwiched between the roller pairs 59, 44, and 45, the sandwiched recording paper 12 is transported in the transport direction 15. On the other hand, when the rollers 60, 62, and 67 rotate backward, the sandwiched recording paper 12 is transported in the direction opposite to the transport direction 15.

[0060] [Second conveying path 71] 2, the second conveying path 71 is a path that passes below the straight portion 34 and above the feed roller 25. The second conveying path 71 is a path that branches off from the straight portion 34 at a branching position 101 that is downstream of the discharge roller pair 44 in the conveying direction 15 and upstream of the reversing roller pair 45 in the conveying direction 15. The second conveying path 71 is a path that merges with the curved portion 33 at a merging position 102 that is upstream of the conveying roller pair 59 in the conveying direction 15.

[0061] The second conveying path 71 is defined by the flap 49, the front guide member 105, the lower surface 50 of the platen 42, the upper surface 120 of the middle guide member 104, the lower surface 19A of the inner guide member 19, the rear guide member 107, and the re-conveying roller pair 30.

[0062] [Front guide member 105] The front guide member 105 faces the flap 49 and defines a portion of the lower side of the second transport path 71. The front guide member 105 is rotatably supported on the third rotation shaft 67A of the reversing roller 67. The front guide member 105 is rotatable about the third rotation shaft 67A. The front guide member 105 is supported by a slider (not shown) that is supported on the internal frame 51 so as to be slidable in the front-rear direction. The front guide member 105 rotates about the third rotation shaft 67A in conjunction with the sliding of the slider in the front-rear direction. The slider slides in the front-rear direction in conjunction with the movement of the feed tray 20 in the front-rear direction.

[0063] [Rear guide member 107] The rear guide member 107 faces the lower surface 19A of the inner guide member 19 and defines a part of the lower side of the second transport path 71. The rear guide member 107 is supported by the internal frame 51.

[0064] [Middle guide member 104] The middle guide member 104 is positioned between the platen 42 and the feed tray 20 in the up-down direction. The middle guide member 104 is positioned between the front guide member 105 and the rear guide member 107 in the front-rear direction. As shown in FIG. 4, the middle guide member 104 is positioned slightly forward of the shaft support portion 51E in the storage space 51C of the inner frame 51. The rear end of the middle guide member 104 is close to the front end of the shaft support portion 51E. As shown in FIGS. 6 and 7, the middle guide member 104 has a box shape that opens downward.

[0065] As shown in FIGS. 4 and 5 , the middle guide member 104 has a right cylindrical portion 235 and a left cylindrical portion 236. The right cylindrical portion 235 and the left cylindrical portion 236 are located at the rear end of the middle guide member 104. The right cylindrical portion 235 has a cylindrical shape extending leftward from the right surface of the middle guide member 104. The right cylindrical portion 235 opens to the right. The right convex portion 231 is inserted into the right cylindrical portion 235. The right cylindrical portion 235 is rotatable relative to the right convex portion 231. The left cylindrical portion 236 has a cylindrical shape extending rightward from the left surface of the middle guide member 104. The left cylindrical portion 236 opens to the left. The left convex portion 232 is inserted into the left cylindrical portion 236. The left cylindrical portion 236 is rotatable relative to the left convex portion 232. In this way, the middle guide member 104 is rotatably attached to the bottom frame 51A. The middle guide member 104 rotates about a central axis 43 that runs along the left-right direction and passes through the centers of the right cylindrical portion 235 and the left cylindrical portion 236. The central axis 43 is an example of a rotation axis.

[0066] The middle guide member 104 is rotatable between a closed position and an open position. As shown in Figures 2 and 7, the closed position is a position where the upper surface 120 of the middle guide member 104 defines the lower side of the second conveying path 71. As shown in Figure 8, the open position is a position where the middle guide member 104 is rotated downward from the closed position. In the open position, the middle guide member 104 hangs down from the central axis 43 due to gravity. The closed position is an example of a first position. The open position is an example of a second position. The middle guide member 104 is an example of a second unit.

[0067] [Release lever 84] As shown in Figures 4 and 7, a release lever 84 is provided for rotating the middle guide member 104 from the closed position to the open position. The release lever 84 is supported on the front end of the middle guide member 104 so as to be movable in the left-right direction. The release lever 84 is positioned in the up-down direction by a guide piece 91 provided on the front end of the middle guide member 104. The release lever 84 has an elongated shape extending in the left-right direction. The length of the release lever 84 in the left-right direction is longer than the length of the middle guide member 104 in the left-right direction. Specifically, the release lever 84 has a left moving body 84A, a right moving body 84B, and a coil spring 84C.

[0068] The left moving body 84A is located at the left end of the middle guide member 104. The left moving body 84A protrudes leftward beyond the left surface of the middle guide member 104. The left moving body 84A abuts against the upper surface of the left plate 512 of the inner frame 51.

[0069] The right moving body 84B is located to the right of the left moving body 84A with a gap therebetween. The right moving body 84B is located at the right end of the middle guide member 104. The right moving body 84B protrudes rightward beyond the right surface of the middle guide member 104. The right moving body 84B abuts against the upper surface of the right plate 511.

[0070] The coil spring 84C is located between the left moving body 84A and the right moving body 84B. The coil spring 84C is compressible in the left-right direction. The left end of the coil spring 84C abuts against the right end of the left moving body 84A. The right end of the coil spring 84C abuts against the left end of the right moving body 84B. The coil spring 84C biases the left moving body 84A to protrude leftward from the left surface of the middle guide member 104, and biases the right moving body 84B to protrude rightward from the right surface of the middle guide member 104. This keeps the left moving body 84A in contact with the upper surface of the left plate 512, and keeps the right moving body 84B in contact with the right plate 511. As a result, the middle guide member 104 is maintained in the closed position.

[0071] On the other hand, the user can move left moving body 84A and right moving body 84B inward in the left-right direction against the biasing force of coil spring 84C, thereby moving left moving body 84A and right moving body 84B to positions where they do not abut on the upper surfaces of left plate 512 and right plate 511, respectively. As a result, the user can rotate middle guide member 104 from the closed position to the open position.

[0072] [Re-conveying roller pair 30] As shown in FIG. 2, the re-conveyance roller pair 30 is located on the second conveyance path 71. The re-conveyance roller pair 30 includes a re-conveyance roller 22 disposed below the second conveyance path 71 and a driven roller 23 disposed above the second conveyance path 71 facing the re-conveyance roller 22. As shown in FIG. 4, two re-conveyance rollers 22 are disposed at a distance in the left-right direction. Each re-conveyance roller 22 is rotatably supported by an intermediate guide member 104. Each re-conveyance roller 22 is driven by the driving force of a conveyance motor transmitted via a second drive transmission mechanism 301 (described later). The driven roller 23 is rotatably supported by a platen 42. The driven roller 23 rotates in accordance with the rotation of the re-conveyance roller 22. When the re-conveyance roller 22 rotates forward due to the reverse driving force of the conveyance motor while the recording paper 12 is sandwiched between the re-conveyance roller pair 30, the sandwiched recording paper 12 is conveyed in a reverse conveyance direction 106.

[0073] [Second drive transmission mechanism 301] As shown in FIGS. 4 and 5 , the second drive transmission mechanism 301 is located in the inner frame 51 and the middle guide member 104. The second drive transmission mechanism 301 transmits the driving force of the conveyance motor supported by the inner frame 51 to the support shaft 28 of the feed unit 16 and the re-conveyance roller 22. Specifically, the second drive transmission mechanism 301 includes a first shaft 311, a transmission gear 312, a first gear 313, a second gear 314, a second shaft 315, a third gear 316, a third shaft 317, a fourth gear 318, a fifth gear 319, a sixth gear 320, a seventh gear 321, a pair of rear arms 322, and a pair of front arms 323. The second drive transmission mechanism 301 is an example of a drive transmission mechanism.

[0074] The first shaft 311 has a cylindrical shape extending in the left-right direction. The first shaft 311 extends parallel to the central axis 43. The first shaft 311 is rotatably supported by the right plate 511 of the bottom frame 51A and the shaft support portion 51E. Specifically, the first shaft 311 is rotatably inserted into the first through hole 201 of the right plate 511 and the second through hole 202, the third through hole 203, and the fourth through hole 204 of the shaft support portion 51E. The gap between the outer circumferential surface of the first shaft 311 and the inner circumferential surfaces of the through holes 201, 202, 203, and 204, i.e., the difference between the radius of the first shaft 311 and the radius of the through holes 201, 202, 203, and 204, is greater than 0.05 mm and less than 2.0 mm. In other words, the first shaft 311 is not supported by bearings on the right plate 511 and the shaft support portion 51E.

[0075] The left end of the first shaft 311 is adjacent to an opposing wall 211 provided to the left of the left end of the first shaft 311 in the shaft support portion 51E. This prevents the first shaft 311 from slipping out to the left from each of the through holes 201, 202, 203, and 204. The right end of the first shaft 311 is adjacent to a retaining member (not shown) provided to the right of the right end of the first shaft 311 in the right plate 511 of the bottom frame 51A, thereby preventing the first shaft 311 from slipping out to the right from each of the through holes 201, 202, 203, and 204.

[0076] The transmission gear 312 is integrally connected to the portion of the first shaft 311 that protrudes rightward from the first through-hole 201. As a result, the transmission gear 312 is supported by the inner frame 51 via the first shaft 311. The transmission gear 312 is rotatable about the first shaft 311. The transmission gear 312 rotates when the driving force of the conveying motor is transmitted to it. When the driving force is transmitted from the conveying motor, the transmission gear 312 rotates integrally with the first shaft 311. The transmission gear 312 is an example of a first drive transmission element.

[0077] The first gear 313 is integrally connected to the first shaft 311. The first gear 313 is located to the left of the center of the first shaft 311 in the left-right direction. The first gear 313 is located in the right cutout portion 252 of the shaft support portion 51E. When the first shaft 311 rotates due to the rotation of the transmission gear 312, the first gear 313 rotates integrally with the first shaft 311 around the first shaft 311.

[0078] The second gear 314 is located in front of the first gear 313. The second gear 314 is located between the shaft support portion 51E and the intermediate guide member 104 in the front-rear direction. The second gear 314 meshes with the first gear 313. The second gear 314 rotates as the first gear 313 rotates.

[0079] The second shaft 315 rotatably supports the second gear 314. As shown in FIGS. 5 and 6, the second shaft 315 has an axle portion 315A and a rotating portion 315B. The axle portion 315A has a cylindrical shape extending in the left-right direction. The axle portion 315A extends parallel to the first shaft 311. The axle portion 315A is located slightly lower than the first shaft 311 (see FIG. 7). The axle portion 315A is inserted into a center hole 314A of the second gear 314 so as to be movable in the left-right direction and rotatable. The rotating portion 315B extends forward from the right end of the axle portion 315A. A rotating tip 315C of the rotating portion 315B is adjacent to the inner surface 104C of the right wall 104B of the middle guide member 104 in the left-right direction. This restricts the rightward movement range of the rotating portion 315B. The left-right direction is an example of an axial direction, and the forward direction is an example of a direction intersecting the axial direction.

[0080] An abutment piece 351 that abuts against the underside of the rotating portion 315B is provided in the internal space of the middle guide member 104. The abutment piece 351 is located slightly spaced to the left of the inner surface 104C of the right wall 104B. The abutment piece 351 abuts against the underside of the rotating portion 315B, thereby restricting the rotation range of the rotating portion 315B. This keeps the rotation tip 315C of the rotating portion 315B close to the inner surface 104C of the right wall 104B. As a result, the rotating portion 315B is prevented from rotating downward and from moving rightward. As a result, the shaft portion 315A is restricted from moving rightward through the center hole 314A of the second gear 314, preventing the second shaft 315 from coming off the second gear 314. The abutment piece 351 is an example of a first abutment. The inner surface 104C is an example of a second contact portion.

[0081] The rotating portion 315B is configured to be elastically deformable in the left-right direction. This allows the user to rotate the rotating portion 315B to a position below the right wall 104B by passing the rotating portion 315B through the lower opening of the middle guide member 104, elastically deforming the rotating portion 315B to the right until it does not abut against the abutment piece 351, and then rotating the rotating tip 315C of the rotating portion 315B in the direction of arrow 111 shown in FIG. 6. As a result, the user can pull the shaft portion 315A out to the right from the center hole 314A of the second gear 314, and remove the second shaft 315 from the second gear 314.

[0082] The third gear 316 is located in front of the second gear 314. The third gear 316 is in mesh with the second gear 314. The third gear 316 rotates as the second gear 314 rotates.

[0083] The third shaft 317 is fixed to the middle guide member 104. The third shaft 317 has a cylindrical shape extending in the left-right direction. The third shaft 317 extends parallel to the shaft portion 315A. The third shaft 317 rotatably supports the third gear 316. The third shaft 317 is located slightly above the shaft portion 315A (see FIG. 7).

[0084] The fourth gear 318 is located in front of the third gear 316. The fourth gear 318 is rotatably supported by the middle guide member 104. The fourth gear 318 meshes with the third gear 316. The fourth gear 318 rotates due to the rotation of the third gear 316.

[0085] The fifth gear 319 is located in front of the fourth gear 318. The fifth gear 319 is fixed to the right end of the support shaft 28 of the feeding unit 16. The fifth gear 319 rotates around the support shaft 28. The fifth gear 319 meshes with the fourth gear 318. The fifth gear 319 rotates integrally with the support shaft 28 due to the rotation of the fourth gear 318.

[0086] The sixth gear 320 is fixed to the support shaft 28 with a slight gap therebetween to the left of the fifth gear 319. The sixth gear 320 rotates around the support shaft 28. The sixth gear 320 is in mesh with the right re-conveyance roller 22. The sixth gear 320 rotates integrally with the support shaft 28 as the support shaft 28 rotates. As a result, the driving force of the conveyance motor is transmitted to the right re-conveyance roller 22.

[0087] As shown in FIG. 4, the seventh gear 321 is fixed to the left end of the support shaft 28. The seventh gear 321 rotates around the support shaft 28. The seventh gear 321 meshes with the left re-conveyance roller 22. The seventh gear 321 rotates integrally with the support shaft 28 due to the rotation of the support shaft 28. As a result, the driving force of the conveyance motor is transmitted to the left re-conveyance roller 22.

[0088] 5 and 7, the pair of rear arms 322 connect the first shaft 311 and the second shaft 315. The pair of rear arms 322 are positioned so as to sandwich the first gear 313 and the second gear 314 in the left-right direction. Specifically, the pair of rear arms 322 have a rear left arm 322A and a rear right arm 322B.

[0089] The rear-left arm 322A is located to the left of the first gear 313 and the second gear 314. The rear-left arm 322A has a flat plate shape that extends in the front-rear and up-down directions. The rear-left arm 322A has a circular rear through-hole 411 and a front through-hole 412 that penetrate in the left-right direction. The rear through-hole 411 is located at the rear end of the rear-left arm 322A. The first shaft 311 is rotatably inserted into the rear through-hole 411. As a result, the rear-left arm 322A is rotatably supported by the first shaft 311. The front through-hole 412 is located at the front end of the rear-left arm 322A. The shaft portion 315A of the second shaft 315 is inserted into the front through-hole 412 so as to be rotatable and movable in the left-right direction. As a result, the rear-left arm 322A is rotatably supported by the shaft portion 315A.

[0090] The rear left arm 322A has an upper restricting piece 415 that protrudes leftward from its left surface. The upper restricting piece 415 is located at the rear end of the rear left arm 322A. The upper restricting piece 415 is located slightly below the rear through-hole 411.

[0091] The rear right arm 322B is located to the right of the first gear 313 and the second gear 314. The rear right arm 322B has the same structure as the rear left arm 322A except for its position. Therefore, elements corresponding to those of the rear left arm 322A are given the same reference numerals as those of the rear left arm 322A and will not be described further. The pair of rear arms 322 are an example of a first arm. The front through-hole 412 is an example of a first connecting hole.

[0092] The pair of front arms 323 connect the second shaft 315 and the third shaft 317. The pair of front arms 323 are positioned so as to sandwich the second gear 314 and the third gear 316 in the left-right direction. Specifically, the pair of front arms 323 have a front left arm 323A and a front right arm 323B.

[0093] The front left arm 323A is adjacent to the left of the rear left arm 322A. The front left arm 323A has a flat plate shape that extends in the front-rear and up-down directions. The front left arm 323A has a circular rear through-hole 413 and a front through-hole 414 that penetrate in the left-right direction. The rear through-hole 413 is located at the rear end of the front left arm 323A. The shaft portion 315A of the second shaft 315 is inserted into the rear through-hole 413 so as to be movable in the left-right direction and rotatable. This allows the front left arm 323A to be rotatably supported by the shaft portion 315A. The front left arm 323A and the rear left arm 322A can rotate independently of each other relative to the second shaft 315. The front through-hole 414 is located at the front end of the front left arm 323A. A third shaft 317 is inserted into the front through-hole 414. The front left arm 323A is rotatably supported by the third shaft 317. The left inner wall 109 of the middle guide member 104 is adjacent to the left surface of the front left arm 323A, thereby preventing the front left arm 323A from slipping off the second shaft 315 and the third shaft 317 to the left.

[0094] The front left arm 323A has a lower regulating piece 416 that protrudes rearward from its rear end. The lower regulating piece 416 is located below the rear through-hole 413. The lower regulating piece 416 abuts against the lower side of the upper regulating piece 415. The lower regulating piece 416 and the upper regulating piece 415 are examples of a regulating portion.

[0095] The front right arm 323B is adjacent to the right of the rear right arm 322B. The right inner wall 108 of the middle guide member 104 is adjacent to the right surface of the front right arm 323B. This prevents the front right arm 323B from slipping off the second shaft 315 and the third shaft 317 to the right. The other structures of the front right arm 323B are the same as those of the front left arm 323A. Therefore, elements corresponding to those of the front left arm 323A are given the same reference numerals as those of the front left arm 323A and will not be described again. The pair of front arms 323 is an example of a second arm. The rear through-hole 413 is an example of a second connecting hole.

[0096] In the second drive transmission mechanism 301, when the first shaft 311 rotates counterclockwise as shown in FIG. 7 due to the forward driving force of the conveyance motor, the second shaft 315 is not fixed, and therefore the meshing of the first gear 313 and the second gear 314 causes the second gear 314 to move upward around the first gear 313. At this time, the second gear 314 attempts to move in a direction that tightly meshes with the first gear 313 and the third gear 316, but the movement of the second gear 314 is blocked by the third gear 316, and therefore the first gear 313 receives a large downward force due to the reaction force from the second gear 314. As a result, the first gear 313 attempts to move significantly downward together with the first shaft 311. At this time, the upper regulating piece 415 abuts against the upper side of the lower regulating piece 416, restricting the downward movement of the pair of rear arms 322. As a result, the first shaft 311 is prevented from moving downward, thereby preventing the first shaft 311 from contacting the inner surfaces of the first through hole 201, the second through hole 202, the third through hole 203, and the fourth through hole 204.

[0097] 7 by the reverse driving force of the conveying motor (when the recording paper 12 is conveyed in the reverse conveying direction 106 on the second conveying path 71), the meshing of the first gear 313 with the second gear 314 causes the second gear 314 to move downward around the first gear 313, and therefore the second gear 314 does not move in a direction that tightly meshes with the first gear 313 and the third gear 316. Therefore, the first gear 313 does not receive a large reaction force from the second gear 314, and therefore does not move significantly downward together with the first shaft 311.

[0098] [Double-sided image recording] Double-sided image recording is a process in which images are recorded on both the first side of the recording paper 12 and the second side opposite to the first side.

[0099] When double-sided image recording is instructed, the forward rotation driving force of the conveyance motor is transmitted to the feed roller 25 via the second drive transmission mechanism 301, the support shaft 28, and the first drive transmission mechanism 27. As a result, the feed roller 25 rotates, and the recording paper 12 is sent from the feed tray 20 to the first conveyance path 65. The recording paper 12 that has passed through the curved portion 33 of the first conveyance path 65 is conveyed along the straight portion 34 in the conveyance direction 15 while being held by the pair of conveyance rollers 59. Ink is ejected from the recording head 38 onto the first side (upper surface) of the recording paper 12 supported by the platen 42, thereby recording an image on the first side of the recording paper 12. The recording paper 12 that has been conveyed along the straight portion 34 in the conveyance direction 15 while the image is being recorded is then conveyed along the straight portion 34 in the conveyance direction 15 while being held by the pair of discharge rollers 44, and comes into contact with the flap 49 in the first state. The flap 49 is pressed down against the biasing force of the biasing member due to its contact with the recording paper 12. As a result, the flap 49 rotates to the second state.

[0100] The recording paper 12 that has passed through the flap 49 is clamped by the reversing roller 67 and transported in the transport direction 15, and when the rear end of the recording paper 12 passes through the flap 49, the flap 49 rotates from the second state to the first state due to the biasing force of the biasing member.

[0101] Thereafter, when the forward rotation drive force of the conveying motor is switched to a reverse rotation drive force, and the reversing roller 67 is switched from forward rotation to reverse rotation, the pair of reversing rollers 45 conveys the recording paper 12 in the direction opposite to the conveying direction 15. The recording paper 12 conveyed in the direction opposite to the conveying direction 15 is guided by the flap 49 in the first state and enters the second conveying path 71.

[0102] The recording paper 12 that has entered the second conveyance path 71 is further conveyed in the reverse conveyance direction 106 by the re-conveyance roller pair 30. At this time, the reverse driving force of the conveyance motor is not transmitted to the feed roller 25, so the recording paper 12 is not sent to the first conveyance path 65. Then, the recording paper 12 that has been conveyed in the reverse conveyance direction 106 along the second conveyance path 71 passes through the junction position 102 and is conveyed again along the curved portion 33 in the conveyance direction 15. The recording paper 12 then reaches the conveyance roller pair 59. Here, the reverse driving force of the conveyance motor is switched to forward driving force, causing the rollers 60, 62, and 67 to switch from reverse rotation to forward rotation. The recording paper 12 is then conveyed in the conveyance direction 15 by the conveyance roller pair 59 and reaches below the recording unit 24. At this time, the second side of the recording paper 12 faces the recording head 38. The recording head 38 ejects ink onto the second side of the recording paper 12 to record an image. Thereafter, the recording paper 12 with images recorded on both sides is conveyed in the conveying direction 15 by the discharge roller pair 44 and the reversing roller pair 45 and discharged onto the discharge tray 21. Note that when an image is recorded only on the first side of the recording paper 12, the reversing roller 67 continues to rotate forward without switching to reverse rotation. As a result, the reversing roller pair 45 conveys the recording paper 12 in the conveying direction 15 and discharges it onto the discharge tray 21.

[0103] [Jam Clearance] Next, a jam clearance when the recording paper 12 is jammed in the first transport path 65 or the second transport path 71 will be described.

[0104] First, the user pulls out the feed tray 20 and the discharge tray 21 from the housing 14 through the opening 13. Next, the user moves the release lever 84 through the opening 13 to a position where it does not abut the upper surfaces of the left plate 512 and the right plate 511, and then rotates the middle guide member 104 from the closed position to the open position as shown in FIG. 8. This causes the platen 42 to rotate around the first rotation shaft 60A by its own weight and reach the release position. As a result, the user can easily access the first transport path 65 and the second transport path 71 through the opening 13, making it easy to clear jams.

[0105] Here, because the positions of the central axis 43 of the middle guide member 104 and the first shaft 311 do not coincide (see FIG. 5 ), the distance between the first gear 313 and the third gear 316 changes as the middle guide member 104 rotates from the closed position to the open position. In the second drive transmission mechanism 301, the first shaft 311 and the second shaft 315 are rotatably connected to a pair of rear arms 322, and the third shaft 317 and the second shaft 315 are rotatably connected to a pair of front arms 323, and the pair of front arms 323 and the pair of rear arms 322 can rotate independently of each other relative to the second shaft 315. Therefore, even if the distance between the first gear 313 and the third gear 316 changes, the pair of rear arms 322 and the pair of front arms 323 rotate, and the second gear 314 moves while remaining engaged with the first gear 313 and the third gear 316.

[0106] [Effects of the embodiment] In the second drive transmission mechanism 301, when the middle guide member 104 rotates between the closed position and the open position, even if the distance between the first gear 313 and the third gear 316 changes, the pair of rear arms 322 and the pair of front arms 323 rotate, and the second gear 314 moves while maintaining a state of meshing with the first gear 313 and the third gear 316. Therefore, after the middle guide member 104 is rotated relative to the internal frame 51, no operation is required to connect the second gear 314.

[0107] In the second drive transmission mechanism 301, the transmission gear 312 and the first gear 313 are integrally connected to the first shaft 311 and rotate integrally with the first shaft 311, thereby enabling space savings compared to when the transmission gear 312 and the first gear 313 are supported on separate shafts.

[0108] In the second drive transmission mechanism 301, the first shaft 311 is not supported via bearings on the right plate 511 of the bottom frame 51A or the shaft support portion 51E. Therefore, any error in the assembly of the middle guide member 104 and the inner frame 51 does not affect the first shaft 311, and resistance to the rotation of the first shaft 311 is unlikely to occur.

[0109] In the second drive transmission mechanism 301, the right plate 511 of the bottom frame 51A has a first through hole 201 into which the first shaft 311 is rotatably inserted. The shaft support part 51E has a second through hole 202, a third through hole 203, and a fourth through hole 204 into which the first shaft 311 is rotatably inserted. This makes it difficult for the first shaft 311 to come off the inner frame 51.

[0110] In the second drive transmission mechanism 301, when the forward driving force of the conveyance motor is transmitted to the first shaft 311, the first shaft 311 rotates counterclockwise in FIG. 7 . Because the second shaft 315 is not fixed, the meshing of the first gear 313 and the second gear 314 causes the second gear 314 to move upward around the first gear 313. As a result, while the second gear 314 attempts to move in a direction that tightly meshes with the first gear 313 and the third gear 316, the movement of the second gear 314 is blocked by the third gear 316. As a result, the first gear 313 receives a large downward force due to the reaction force from the second gear 314. As a result, the first gear 313 attempts to move significantly downward together with the first shaft 311. At this time, the upper regulating piece 415 abuts against the upper side of the lower regulating piece 416, restricting the downward movement of the pair of rear arms 322. As a result, the first shaft 311 is prevented from moving downward, thereby preventing the first shaft 311 from contacting the inner surfaces of the first through hole 201, the second through hole 202, the third through hole 203, and the fourth through hole 204.

[0111] In the second drive transmission mechanism 301, as shown in FIGS. 5 and 6 , the rotation tip 315C of the rotation portion 315B of the second shaft 315 is close to the inner surface 104C of the right wall 104B of the middle guide member 104, and therefore, rightward movement of the rotation portion 315B is restricted by the inner surface 104C. The lower side of the rotation portion 315B abuts against the abutment piece 351, and therefore, downward rotation of the rotation portion 315B is restricted. As a result, rightward movement of the shaft portion 315A is restricted from the center hole 314A of the second gear 314, the front through-holes 412 of the pair of rear arms 322, and the rear through-holes 413 of the pair of front arms 323, and therefore, the second shaft 315 is prevented from coming off the second gear 314, the pair of rear arms 322, and the pair of front arms 323.

[0112] In the second drive transmission mechanism 301, the rotating portion 315B is configured to be elastically deformable in the left-right direction. Thus, the user can rotate the rotating portion 315B to a position below the right wall 104B by elastically deforming the rotating portion 315B to the right until it does not abut against the abutment piece 351 through the lower opening of the middle guide member 104 and then rotating the rotating tip 315C of the rotating portion 315B in the direction of arrow 111 shown in FIG. 6 . As a result, the user can pull the shaft portion 315A to the right out of the center hole 314A of the second gear 314, the front through-holes 412 of the pair of rear arms 322, and the rear through-holes 413 of the pair of front arms 323, thereby removing the second shaft 315 from the second gear 314, the pair of rear arms 322, and the pair of front arms 323. This allows the user to remove the second gear 314 from between the first gear 313 and the third gear 316. As a result, the connection between the shaft support portion 51E and the intermediate guide member 104 in the second drive transmission mechanism 301 is released, so that the user can easily remove the intermediate guide member 104 from the internal frame 51.

[0113] [Variations] In the second drive transmission mechanism 301, the transmission gear 312 to which the driving force of the carry motor is transmitted is integrally connected to the first shaft 311, but this is not limiting as long as the driving force of the carry motor can be transmitted to the first shaft 311. For example, instead of the transmission gear 312, the motor shaft of the carry motor may be integrally connected to the first shaft 311.

[0114] In the second drive transmission mechanism 301, the second gear 314 is rotatably supported on the second shaft 315, but the second gear 314 may be integrally connected to the second shaft 315 to rotate integrally with the second shaft 315. In this case, the rotating portion 315B and the abutment piece 351 of the second shaft 315 may be omitted.

[0115] In the second drive transmission mechanism 301, the third shaft 317 is fixed to the intermediate guide member 104, but may be rotatably supported by the intermediate guide member 104. In this case, the third gear 316 is integrally connected to the third shaft 317, and thereby rotates integrally with the third shaft 317 around the third shaft 317.

[0116] In the second drive transmission mechanism 301, the first shaft 311 is not supported by the inner frame 51 via a bearing, but may be supported by the inner frame 51 via a bearing.

[0117] In the second drive transmission mechanism 301, the upper regulating piece 415 and the lower regulating piece 416 are provided, but it is sufficient to provide at least one of the upper regulating piece 415 and the lower regulating piece 416 as long as it can regulate the rotation range of the pair of rear arms 322 relative to the pair of front arms 323. Also, the upper regulating piece 415 and the lower regulating piece 416 may be omitted.

[0118] In the second drive transmission mechanism 301, the rotating tip 315C of the rotating part 315B of the second shaft 315 comes close to the inner surface 104C of the right wall 104B of the middle guide member 104, and the inner surface 104C prevents the rotating part 315B from moving to the right, but this is not limited to this as long as the rotating part 315B can be prevented from moving to the right.

[0119] For example, as shown in FIG. 9 , the right wall 104B may have a right through-hole 104D through which a pivot tip 315C of a pivot portion 315B of the second shaft 315 passes to the right. The pivot tip 315C of the pivot portion 315B is located close to the left end of the right plate 511 through the right through-hole 104D. As a result, the left end of the right plate 511 prevents the pivot portion 315B from moving rightward. The right through-hole 104D extends in an arc shape to the lower end of the middle guide member 104 so that the pivot portion 315B can pivot downward below the right wall 104B. As a result, the pivot tip 315C of the pivot portion 315B can pivot downward below the right wall 104B to a position where it is not close to the left end of the right plate 511. The contact piece 351 that contacts the underside of the rotating part 315B may prevent the rotating part 315B from rotating downward by extending leftward from the left end of the right plate 511. In this case, the rotating tip 315C may be elastically deformed in the front-rear direction to a position where it does not contact the contact piece 351.

[0120] In the second drive transmission mechanism 301, the rotating part 315B is configured to be elastically deformable in the left-right direction, but it does not have to be elastically deformable in the left-right direction. In this case, the second shaft 315 does not have to be detachable from the second gear 314, the pair of rear arms 322, and the pair of front arms 323.

[0121] In the second drive transmission mechanism 301, the transmission gear 312 and the first gear 313 are supported on the first shaft 311, but they may be supported on separate shafts. In this case, as shown in FIG. 10 , the second drive transmission mechanism 301 further includes a fourth shaft 361 and a drive gear 362. The first shaft 311 may be fixed to the right plate 511 and the shaft support portion 51E of the inner frame 51. In this case, the first gear 313 is rotatably supported on the first shaft 311.

[0122] The fourth shaft 361 is located rearward of the first shaft 311. The fourth shaft 361 extends in the left-right direction parallel to the first shaft 311. A right end portion of the fourth shaft 361 is rotatably supported by a right bearing 363 provided on the right plate 511. The right bearing 363 is an example of a bearing. A left end portion of the fourth shaft 361 is rotatably supported by a left bearing 364 provided on the shaft support portion 51E. The left bearing 364 is an example of a bearing.

[0123] The transmission gear 312 is integrally connected to the fourth shaft 361 on the right side of the left bearing 364. As a result, the transmission gear 312 is supported by the inner frame 51 via the fourth shaft 361. The transmission gear 312 rotates integrally with the fourth shaft 361 around the fourth shaft 361. The transmission gear 312 meshes with the first gear 313. Note that another gear may be interposed between the transmission gear 312 and the first gear 313.

[0124] The drive gear 362 is integrally connected to the right end of the fourth shaft 361. The drive gear 362 rotates integrally with the fourth shaft 361 around the fourth shaft 361. The drive force of the transport motor is transmitted to the second drive gear 362. When the drive force of the transport motor is transmitted to the drive gear 362, the drive gear 362 rotates integrally with the fourth shaft 361. This transmits the drive force of the transport motor to the transmission gear 312. The drive gear 362 is an example of a second drive transmission element. In this way, the fourth shaft 361 is rotatably supported by the inner frame 51 via the right bearing 363 and the left bearing 364, and is therefore less likely to bend. This makes it easier to transmit the drive force of the transport motor to the re-conveyance roller 22 and the feeding unit 16 via the second drive transmission mechanism 301.

[0125] 10, the drive gear 362 to which the driving force of the carry motor is transmitted is integrally connected to the fourth shaft 361, but this is not limiting as long as the driving force of the carry motor can be transmitted to the fourth shaft 361. For example, instead of the drive gear 362, the motor shaft of the carry motor may be integrally connected to the fourth shaft 361.

[0126] As shown in FIG. 10 , a retaining member 367 is provided on the right plate 511 to the right of the right end of the drive gear 362. A left surface 367A of the retaining member 367 is adjacent to the right end of the drive gear 362. The retaining member 367 has a cylindrical extending portion 367B extending leftward from the left surface 367A. The extending portion 367B is inserted into a center hole of the drive gear 362. The drive gear 362 is rotatable relative to the extending portion 367B inserted into the center hole. This prevents the fourth shaft 361 from coming off the right bearing 363 and the left bearing 364 to the right. [Explanation of symbols]

[0127] 51 Internal frame (first unit) 104 Middle guide member (second unit) 104C...Inner surface (second contact part) 201... First through hole (insertion hole) 301 Second drive transmission mechanism (drive transmission mechanism) 311···First shaft 312 Transmission gear (first drive transmission element) 313···1st gear 314···Second gear 315···Second shaft 315A...Shaft part 315B···Rotating part 316···Third gear 317···Third shaft 322: Pair of rear arms (first arms) 323: Pair of front arms (second arms) 351...Abutting piece (first abutting part) 361···4th shaft 362 Drive gear (second drive transmission element) 364 Left bearing (bearing) 415...Top regulation piece (regulation part) 416...Lower regulation piece (regulation part)

Claims

1. A first unit; a second unit rotatably attached to the first unit; a first drive transmission element that transmits a drive force; a first gear driven by a driving force from the first drive transmission element; a first shaft to which the first gear is connected, extending parallel to the rotation axis of the second unit and attached to the first unit; a second gear that meshes with the first gear; a second shaft to which the second gear is connected and which extends parallel to the first shaft; a third gear that meshes with the second gear; a third shaft to which the third gear is connected, extending parallel to the second shaft and attached to the second unit; a first arm rotatably supported by the first shaft and the second shaft; a second arm rotatably supported on the second shaft and the third shaft, a drive transmission mechanism in which the first arm and the second arm are rotatable relative to the second shaft independently of each other;

2. the first gear rotates integrally with the first shaft, 2. The drive transmission mechanism according to claim 1, wherein the first shaft is coupled to the first drive transmission element and rotates with rotation of the first drive transmission element.

3. 3. The drive transmission mechanism according to claim 2, wherein the first shaft is not supported by the first unit via a bearing.

4. The drive transmission mechanism according to claim 3 , wherein the first unit has an insertion hole through which the first shaft is inserted.

5. the second unit is rotatable between a first position and a second position rotated downward from the first position, 5. The drive transmission mechanism according to claim 4, wherein at least one of the first arm and the second arm has a restricting portion that restricts a rotation range of the first arm relative to the second arm.

6. The drive transmission mechanism includes: a second drive transmission element that transmits a drive force; a fourth shaft driven by the driving force from the second drive transmission element, the first drive transmission element directly transmits the drive force from the fourth shaft to the first gear, 2. The drive transmission mechanism according to claim 1, wherein the fourth shaft is rotatably supported by the first unit via a bearing.

7. The second shaft is a shaft portion inserted through a first connecting hole located in the first arm and a second connecting hole located in the second arm so as to be axially movable and rotatable; a rotating portion extending from the shaft portion in a direction intersecting the axial direction, 2. The drive transmission mechanism according to claim 1, further comprising: a first abutment portion that abuts against the rotating portion to restrict a rotation range of the rotating portion; and a second abutment portion that abuts against the rotating portion to restrict a movement range of the rotating portion in the axial direction.

8. 8. The drive transmission mechanism according to claim 7, wherein the rotating portion is movable to a position where it does not contact the first contact portion and the second contact portion by rotating while being elastically deformed.

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