JP2016068445A - Image recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image recording device capable of suppressing the positional shifting of a recording image caused by the positional shifting of a recording medium accompanying the switching of the transmission state of a driving force.SOLUTION: The device includes, in order to cause a conveying roller part to convey a recording medium in a conveying direction or a reverse conveying direction, preparation processing (S15) including a forward/reverse operation for forwarding/reversing a driving force in a state where the force of moving from one of a first position and a second position to the other has been added to a moving gear, program searching processing (S17) for causing the conveying roller part to convey the recording medium in a conveying direction to a position facing a recording part, correction processing (S16) for correcting the positional shifting of the recording medium accompanying the forward/reverse operation in the preparation processing by increasing/decreasing the rotation amount of the driving force in the preparation processing or the program searching processing, and recording processing (S18) for causing a recording part to record an image on the recording medium set to face the recording part by the program searching processing.SELECTED DRAWING: Figure 9

Description

  The present invention relates to an image recording apparatus including a transport unit that can transport a recording medium in a transport direction and a reverse transport direction.

  2. Description of the Related Art Conventionally, there is known an image recording apparatus that includes a transport unit that can transport a recording medium in a transport direction and a reverse transport direction, and a recording unit that records an image on the recording medium transported by the transport unit. For example, Patent Document 1 discloses an image recording apparatus that conveys a recording medium in a conveyance direction and a reverse conveyance direction by switching a transmission state of a driving force from a conveyance motor to a conveyance unit driven by the conveyance motor. Yes. Further, the position of the recording medium is generally specified by the rotation amount of the transport motor.

JP 2013-203503 A

  However, in the image recording apparatus described in Patent Document 1, it is necessary to rotate the transport motor forward and backward when switching the transmission state of the driving force. Here, since the timing at which the transmission state is switched during forward / reverse rotation of the drive source is uncertain, the estimated position of the recording medium specified from the rotation amount after forward / reverse rotation of the transport motor and the forward / backward rotation of the transport motor An error may occur between the actual position of the recording medium moved by reverse rotation. If this error occurs, an image may not be recorded at an appropriate position on the recording medium.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an image recording apparatus that suppresses a positional shift of a recorded image caused by a positional shift of a recording medium accompanying a switching of a driving force transmission state. There is to do.

  An image recording apparatus according to the present invention includes a transport roller unit capable of forward rotation for transporting a recording medium in a transport direction and reverse rotation for transporting a recording medium in a reverse transport direction opposite to the transport direction, and the transport roller. A recording unit for recording an image on a recording medium conveyed by the unit, a drive source capable of normal rotation and reverse rotation, a normal rotation state in which the conveyance roller unit is normally rotated by normal rotation of the drive source, and the drive source A driving force transmission unit capable of changing the state to a reverse rotation state in which the conveyance roller unit is reversely rotated by reversing the rotation, and a control unit. The driving force transmission unit transmits a forward rotation driving force of the driving source to the transport roller unit, and a first transmission unit that does not transmit a reverse driving force of the driving source to the transport roller unit, and a reverse rotation of the driving source. A second transmission unit that transmits driving force to the transport roller unit; and a first position in the forward rotation state; a second position in the reverse rotation state; and a forward / reverse rotation of the drive source is transmitted. The driving source that is transmitted through the meshed moving gear, and is disposed at a position that is separated from the rotating gear and the moving gear at the first position and meshed with the moving gear at the second position. And a driven gear that transmits the reverse driving force to the second transmission portion. The control unit applies a force for moving the recording medium from one of the first position and the second position to the other in order to cause the transport roller unit to transport the recording medium in the transport direction and the reverse transport direction. A preparation process for changing the state of the driving force transmitting portion from one of the forward rotation state and the reverse rotation state to the other by driving the drive source forward and backward by rotating the drive source forward and backward in a state applied to the drive source; and After the preparation process, the driving source is driven to cause the conveyance roller unit to convey the recording medium in the conveyance direction to a position facing the recording unit, and the forward / reverse operation in the preparation process. Correction processing for correcting the displacement of the position of the recording medium by increasing or decreasing the amount of rotation of the drive source in the preparation processing or the cue processing, and the cue processing Thus performing a recording process for recording an image on the recording unit to a recording medium which is opposed to the recording portion.

  The positional deviation of the recording medium may be caused by forward / reverse operation of the transport motor when switching the gear meshing state. Therefore, as described above, the positional deviation of the recording medium is corrected by increasing or decreasing the rotation amount of the drive source in the preparation process or the cueing process. As a result, it is possible to suppress displacement of the recorded image due to switching of the transmission state of the driving force.

  According to the present invention, since the positional deviation of the recording medium is corrected by increasing or decreasing the conveyance amount in the preparation process or the cueing process, the positional deviation of the recorded image due to the switching of the driving force transmission state is suppressed. Can do.

1A and 1B are perspective views of a multifunction machine 10 as an example of an embodiment of the present invention. FIG. 1A is a view from the front side, and FIG. 1B is a view from the back side. FIG. 2 is a perspective view of the recording medium 32 and the media tray 31. FIG. 3 is a longitudinal sectional view schematically showing the internal structure of the printer unit 11. FIG. 4 is a plan view of the recording unit 24. 5A and 5B are schematic diagrams of the first transmission unit 72 and the feeding transmission unit 91. FIG. 5A shows a state in which the conveyance motor 71 is rotated forward, and FIG. 5B shows a state in which the conveyance motor 71 is reversed. Show. 6A and 6B are perspective views of the switching mechanism 80, where FIG. 6A shows a state where the moving gear 81 is in the first position, and FIG. 6B shows a state where the moving gear 81 is in the second position. 7A and 7B are schematic views of the first transmission unit 72 and the second transmission unit 94, where FIG. 7A shows a state in which the conveyance motor 71 is rotated forward, and FIG. 7B shows a state in which the conveyance motor 71 is reversed. Show. FIG. 8 is a block diagram of the control unit 130. FIG. 9 is a flowchart of the image recording process. FIG. 10 is a flowchart of the preparation process.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings as appropriate. The embodiment described below is merely an example of the present invention, and it is needless to say that the embodiment of the present invention can be changed as appropriate without departing from the gist of the present invention. In the following description, the vertical direction 7 is defined on the basis of the state in which the multifunction machine 10 is installed (state in FIG. 1), and the front-rear direction 8 is defined with the front side of the multifunction machine 10 as the front side. A left-right direction 9 is defined when the machine 10 is viewed from the front side (front side).

[Overall configuration of MFP 10]
A multifunction machine 10 (an example of an image recording apparatus according to the present invention) shown in FIG. 1A includes a casing 14 configured in a generally thin rectangular parallelepiped shape, and a feeding tray mounted in a lower portion of the casing 14. 20. The feeding tray 20 can support a plurality of sheets 12.

  Inside the housing 14, a discharge space 13 for discharging the paper 12 (see FIG. 3) is formed above the front portion of the feed tray 20 mounted on the multifunction machine 10. A discharge tray 21 that supports the discharged paper 12 is disposed below the discharge space 13. A display unit 16 is disposed on the upper surface of the housing 14 located above the discharge space 13. As shown in FIG. 1B, a rear opening 36 is formed in the rear portion of the housing 14.

  The multifunction machine 10 has a function of recording an image on the paper 12 and also has a function of recording an image on the surface of the recording medium 32 shown in FIG. The recording medium 32 refers to, for example, a CD-ROM or DVD-ROM. The recording medium 32 is supported on a media tray 31 dedicated to the multifunction machine 10 shown in FIG. The media tray 31 supporting the recording medium 32 is inserted into the casing 14 by the user along the tray guide 30 disposed in the discharge space 13 of the casing 14 as shown in FIG. Is done. The media tray 31 and the recording medium 32 supported by the media tray 31 are other examples of the recording medium.

  The upper surface of the media tray 31 has a color (for example, black) whose light reflectance is lower than that of the recording medium 32 (for example, white). A first reference line 32 </ b> A in FIG. 2 is a virtual line that passes through the center of the recording medium 32 supported by the media tray 31 and extends in the short direction of the media tray 31. The second reference line 32 </ b> B is a virtual line that passes through the center of the recording medium 32 supported by the media tray 31 and extends in the longitudinal direction of the media tray 31.

  As shown in FIG. 3, the multifunction machine 10 includes a printer unit 11 inside a housing 14. The printer unit 11 records an image on the paper 12 or the recording medium 32 by an inkjet method. A feeding unit 15 that feeds the paper 12 supported by the feeding tray 20 to the first conveyance path 33 is disposed below the printer unit 11. The feeding unit 15 includes a feeding roller 25 that feeds the paper 12 upward toward the rear side. The feed roller 25 is rotatably supported by a support arm 26. The feed roller 25 is capable of forward rotation for feeding the paper 12 to the first transport path 33 by a reverse driving force of a transport motor 71 (see FIG. 5) described later.

  The first transport path 33 is a space behind the interior of the housing 14 and refers to a space defined by path members that are arranged to face each other with a space therebetween. A back surface opening 36 formed in the back surface of the housing 14 communicates with the upper portion of the first transport path 33. Hereinafter, the direction in the first conveyance path 33 from the feeding tray 20 side to the first conveyance roller unit 54 side is referred to as “conveyance direction”.

  Further, a second transport path 34 along which the paper 12 transported through the first transport path 33 is transported forward exists along the front-rear direction 8. The second conveyance path 34 reaches the discharge space 13 from the downstream end portion of the first conveyance path 33 through the first conveyance roller unit 54, the recording unit 24 and the platen 42, and the second conveyance roller unit 55. ing. The printer unit 11 is configured so that the media tray 31 can enter the second transport path 34 from the front side of the multifunction machine 10 through the discharge space 13. Hereinafter, the direction from the rear side to the front side in the second transport path 34 is referred to as “transport direction”. On the other hand, the direction from the front side to the rear side in the second conveyance path 34 is referred to as “reverse conveyance direction” which is opposite to the conveyance direction.

  As shown in FIG. 3, a registration sensor (an example of a first sensor) 17 is disposed on the upstream side in the transport direction from the first transport roller unit 54. The registration sensor 17 abuts on the paper 12 fed by the feed roller 25 toward the first transport roller unit 54 and the media tray 31 transported in the reverse transport direction, thereby generating a first detection signal. Output. The first detection signal is a signal indicating that the paper 12 or the media tray 31 exists at the installation position (an example of the detection position) of the registration sensor 17.

  The printer unit 11 includes a first conveyance roller unit 54, a recording unit 24, a platen 42, and a second conveyance roller unit 55. The first transport roller unit 54 is disposed upstream of the recording unit 24 in the transport direction, and the second transport roller unit 55 is disposed downstream of the recording unit 24 in the transport direction.

  The first transport roller unit 54 includes an upper first transport roller 60 and a lower pinch roller 61. The first transport roller 60 rotates when the driving force of the transport motor 71 is transmitted. The pinch roller 61 is movable in the vertical direction 7. The first transport roller unit 54 can change between a contact state in which the pinch roller 61 is in contact with the first transport roller 60 and a separated state in which the pinch roller 61 is separated from the first transport roller 60. . The conveyance motor 71 or the conveyance motor 71 and the first roller 60 are an example of a drive source.

  The second transport roller unit 55 includes a lower second transport roller 62 and an upper spur roller 63. The second transport roller 62 is attached to the second roller shaft 62A so as to be integrally rotatable. The second transport roller 62 is rotated by the driving force of the transport motor 71 transmitted through the first transport roller 60. The second transport roller 62 is movable in the up-down direction 7. The state of the second transport roller 55 can be changed between a contact state in which the second transport roller 62 is in contact with the spur roller 63 and a separated state in which the second transport roller 62 is separated from the spur roller 63. .

  The first conveyance roller portion 54 and the second conveyance roller portion 55 in the contact state can convey the paper 12 while sandwiching it. On the other hand, the first transport roller unit 54 and the second transport roller unit 55 in the separated state can transport the media tray 31 while sandwiching it. In addition, the first transport roller 60 and the second transport roller 62 are configured to perform forward rotation for transporting the paper 12 and the media tray 31 in the transport direction by the driving force of the transport motor 71 transmitted through the driving force transmission unit 70, and the media tray. It is possible to perform reverse rotation for transporting 31 in the reverse transport direction.

  The platen 42 is disposed opposite the recording unit 24 between the first conveyance roller unit 54 and the second conveyance roller unit 55. The platen 42 supports the paper 12 that is transported through the second transport path 34. The platen 42 is movable in the vertical direction 7. The platen 42 moves to a proximity position where the interval with the recording unit 24 is suitable for recording an image on the paper 12 and a separation position suitable for recording an image on the recording medium 32 supported by the media tray 31. Is possible.

  As shown in FIG. 3, the recording unit 24 includes a carriage 40 and a recording head 39. Further, a first guide rail 56 and a second guide rail 57 are arranged on the upper side of the platen 42. The carriage 40 is supported by the first guide rail 56 and the second guide rail 57, and reciprocates along the left-right direction 9 by forward and reverse rotation of the carriage motor 103 (see FIG. 8). The recording head 39 is formed with a nozzle 39A that ejects ink downward.

  As shown in FIG. 4, an opening 56 </ b> A is formed at an end portion on the right side of the platen 42 in the first guide rail 56. A switching mechanism 80 (see FIG. 6) described later is disposed below the first guide rail 56 around the opening 56A. The switching lever 86 extending upward from the switching mechanism 80 reaches the upper side of the first guide rail 56 (that is, the movement path of the carriage 40) through the opening 56A.

  As shown in FIG. 3, the carriage 40 has a media sensor (an example of a second sensor) 18 mounted on the rear side of the recording head 39. The media sensor 18 includes a light emitting unit composed of a light emitting diode or the like, and a light receiving unit composed of an optical sensor or the like. The light emitted from the light emitting unit irradiates a predetermined amount of light toward the platen 42. The light irradiated to the platen 42 is reflected by the platen 42 or a transported medium (for example, the paper 12, the media tray 31, or the recording medium 32) on the platen 42, and the reflected light is received by the light receiving unit. The media sensor 18 outputs a second detection signal corresponding to the amount of light received by the light receiving unit to the control unit 130. The second detection signal is a signal indicating that the sheet 12 or the media tray 31 exists at a position facing the carriage 40.

  The second guide rail 57 is provided with a strip-shaped encoder strip 38 </ b> B extending in the left-right direction 9. As shown in FIG. 4, the carriage 40 is equipped with an encoder sensor 38A. In the process in which the carriage 40 moves in the left-right direction 9, the encoder sensor 38 </ b> A reads the encoder strip 38 </ b> B to generate a pulse signal, and outputs the generated pulse signal to the control unit 130. The encoder sensor 38A and the encoder strip 38B constitute the carriage sensor 38 shown in FIG.

[Driving force transmission unit 70]
As shown in FIGS. 5 to 7, the driving force transmission unit 70 transmits the driving force of the conveyance motor 71 to the feeding roller 25, the first conveyance roller 60, and the second conveyance roller 62. The driving force transmission unit 70 is in a first state (an example of a normal rotation state) in which the first conveyance roller unit 54 and the second conveyance roller unit 55 are normally rotated by the normal rotation of the conveyance motor 71, and in the first state by the reverse rotation of the conveyance motor 71. The state can be changed to a second state (an example of a reverse rotation state) in which the first transport roller unit 54 and the second transport path roller unit 55 are rotated in reverse.

  The driving force transmission unit 70 includes a first transmission unit 72, a switching mechanism 80, a feeding transmission unit 91, and a second transmission unit 94. The first transmission unit 72 transmits the driving force of the conveyance motor 71 to the first conveyance roller 60 and the second roller shaft 62A. The feeding transmission unit 91 transmits the driving force of the conveyance motor 71 transmitted through the switching mechanism 80 to the feeding roller 25. The second transmission unit 94 transmits the driving force of the transport motor 71 transmitted through the switching mechanism 80 to the second roller shaft 62 </ b> A of the second transport roller 62. The switching mechanism 80 transmits the driving force of the conveyance motor 71 to the feeding transmission unit 91 and not to the second transmission unit 94 in the first state. Further, the switching mechanism 80 transmits to the second transmission unit 94 and does not transmit to the feeding transmission unit 91 in the second state.

[First transmission unit 72]
The first transmission unit 72 transmits the forward driving force and the reverse driving force of the transport motor 71 to the first transport roller 60 in the first state and the second state. Further, in the first state and the second state, the first transmission unit 72 transmits the forward drive force of the transport motor 71 to the second transport roller 62 and the reverse drive force of the transport motor 71 to the second transport roller 62. Do not communicate.

  As shown in FIG. 5, the first transmission unit 72 spans the pulley 72A that rotates integrally with the motor shaft of the transport motor 71, the pulley 72B that rotates together with the first transport roller 60, and the pulleys 72A and 72B. And an endless annular belt 72C. As a result, the first transmission unit 72 rotates the first transport roller 60 forward by the forward driving force of the transport motor 71 and reversely rotates the first transport roller 60 by the reverse driving force of the transport motor 71.

  The first transmission portion 72 includes a first gear 73A that is attached to the first conveying roller 60 so as to be integrally rotatable, a second gear 73B that meshes with the first gear 73A, and a pulley 73C that integrally rotates with the second gear 73B. And. Furthermore, the 1st transmission part 72 is provided with the pulley 73E attached to the 2nd roller shaft 62A via the one-way clutch 73G, and the endless annular belt 73F wound around the pulleys 73C and 73E.

  The one-way clutch 73G transmits the forward drive force of the transport motor 71 transmitted through the first transport roller 60 to the second roller shaft 62A, and the reverse drive force of the transport motor 71 transmitted through the first transport roller 60 is the first. Not transmitted to the two-roller shaft 62A. Accordingly, the first transmission unit 72 rotates the second conveyance roller 62 in the normal direction by the normal rotation driving force of the conveyance motor 71 and does not transmit the reverse rotation driving force of the conveyance motor 71 to the second conveyance roller 62.

  Further, the encoder disk 19 </ b> A is attached to the first transport roller 60 so as to rotate integrally with the first transport roller 60. An optical sensor 19B is disposed opposite the encoder disk 19A. The optical sensor 19 </ b> B reads the encoder disk 19 </ b> A that rotates together with the first transport roller 60 to generate a pulse signal, and outputs the generated pulse signal to the control unit 130. The encoder disk 19 </ b> A and the optical sensor 19 </ b> B constitute a rotary encoder 19.

[Switching mechanism 80]
As shown in FIG. 6A, the switching mechanism 80 includes a support shaft 81A, a moving gear 81 that is supported by the support shaft 81A so as to be rotatable and movable in the axial direction (left-right direction 9), A first driven gear 83 and a second driven gear 84 (an example of a driven gear) arranged side by side in the left-right direction 9 are provided below the gear 81.

  The moving gear 81 is configured to be movable along the support shaft 81A to the first position and the second position on the right side of the first position. The moving gear 81 is meshed with a first gear 77 (see FIG. 5) attached to the first conveying roller 60. The first gear 77 maintains the meshed state with the moving gear 81 even when the moving gear 81 moves in the left-right direction 9. The moving gear 81 rotates when the driving force of the conveying motor 71 is transmitted through the first conveying roller 60 and the first gear 77.

  The 1st driven gear 83 and the 2nd driven gear 84 are arrange | positioned in the state which each side faced mutually. The first driven gear 83 is meshed with the moving gear 81 at the first position, and is separated from the moving gear 81 at the second position. The second driven gear 84 is separated from the moving gear 81 at the first position and meshed with the moving gear 81 at the second position. That is, the driving force of the conveyance motor 71 is transmitted to the first driven gear 83 through the moving gear 81 at the first position, and is transmitted to the second driven gear 84 through the moving gear 81 at the second position.

  On the support shaft 81A, a pressing member 85 is supported on the right side of the moving gear 81 so as to be slidable in the left-right direction 9. The moving gear 81 is biased rightward by the first spring. The pressing member 85 is urged leftward by the second spring. The biasing force of the second spring is greater than the biasing force of the first spring. As a result, the moving gear 81 and the pressing member 85 are biased leftward. Further, the switching lever 86 described above extends upward from the pressing member 85.

  A holding portion 87 that holds the switching lever 86 at a predetermined position in the left-right direction 9 is fixed below the opening 56 </ b> A provided in the first guide rail 56. The holding portion 87 is formed with an opening 87A through which the switching lever 86 passes. The switching lever 86 passes through the opening 87A of the holding portion 87 and the opening 56A (see FIG. 3) of the first guide rail 56. The upper end portion of the switching lever 86 is located in the passage region of the carriage 40 above the first guide rail 56 and outside the passage region of the transported medium on the platen 42.

  The switching lever 86 moves the pressing member 85 to the right by contacting the carriage 40 that moves to the right. At this time, a force for moving the moving gear 81 to the right is applied to the moving gear 81 from the first spring. Further, the switching lever 86 moved to the right end of the holding portion 87 by the carriage 40 and separated from the carriage 40 is returned to the position shown in FIG. 6A by the urging force of the second spring. That is, the carriage 40 applies a force for moving the moving gear 81 from the first position to the second position to the moving gear 81 through the switching lever 86. Further, the second spring applies a force that moves the moving gear 81 from the second position to the first position to the moving gear 81 through the switching lever 86.

  The moving gear 81 may not be able to move even when a rightward or leftward force is applied. This is because when the moving gear 81 is moved, the teeth of the moving gear 81 overlap with the teeth of the first driven gear 83 and the second driven gear 84 that are the moving destinations. In order to eliminate interference between these teeth, it is necessary to rotate the moving gear 81 forward and backward. The forward / reverse rotation of the moving gear 81 can be realized by rotating the transport motor 71 forward / reversely. That is, by causing the carriage motor 71 to rotate forward and backward after the carriage 40 is brought into contact with the switching lever 86, the moving gear 81 is moved to the first position and the first position at any timing during forward and reverse rotation of the carry motor 71. It is possible to move from one of the two positions to the other.

  When the switching lever 86 is held by the holding portion 83 at the position shown in FIG. 6A, the moving gear 81 meshes with the first driven gear 83 at the first position. The state of the driving force transmission unit 70 at this time is the first state. When the switching lever 86 is held by the holding portion 83 at the position shown in FIG. 6B, the moving gear 81 meshes with the second driven gear 84 at the second position. The state of the driving force transmission unit 70 at this time is the second state. That is, the driving force transmission unit 70 is switched between the first state and the second state by the movement of the carriage 40.

[Feeding transmission part 91]
The feeding transmission unit 91 transmits the driving force of the conveyance motor 71 transmitted through the switching mechanism 80 to the feeding roller 25 when the driving force transmission unit 70 is in the first state. As shown in FIG. 5, the rotation of the first driven gear 83 is transmitted to the second gear 91B by the first gear 91A. The rotation of the first pulley 91C that rotates integrally with the second gear 91B is transmitted to the second pulley 91E by the first belt 91D. The rotation of the third gear 91F that rotates integrally with the second pulley 91E is transmitted to the fourth gear 91G.

  A fourth gear 91G and a sun gear 91J are attached to the rotation shaft 91H so as to be integrally rotatable. Therefore, the sun gear 91J rotates integrally with the fourth gear 91G. The sun gear 91J meshes with a pendulum gear 91M supported at the tip of a support arm 91K that is rotatably attached to the rotation shaft 91H. The pendulum gear 91M revolves around the sun gear 91J and moves toward and away from the intermediate gear 91N while rotating in the forward and reverse directions along with the forward and reverse rotation of the sun gear 91J.

  Specifically, as shown in FIG. 5A, when the forward driving force of the transport motor 71 is transmitted and the sun gear 91J rotates, the pendulum gear 91M is separated from the intermediate gear 91N. That is, the forward driving force of the conveyance motor 71 is not transmitted to the intermediate gear 91N. On the other hand, as shown in FIG. 5B, when the reverse driving force of the transport motor 71 is transmitted and the sun gear 91J rotates, the pendulum gear 91M meshes with the intermediate gear 91N. Thereby, the reverse driving force of the conveyance motor 71 is transmitted to the intermediate gear 91N through the pendulum gear 91M.

  The rotation of the intermediate gear 91N is transmitted through the gear 91R to the third pulley 91S constituting the belt transmission mechanism 91P. The rotation of the third pulley 91S is transmitted to the fourth pulley 91V that can rotate integrally with the feeding roller 25 by the transmission belt 91T. As a result, the feeding transmission unit 91 increases the forward driving force of the transport motor 71 in a state where the switching lever 86 is held at the position of FIG. 6A (that is, the first state of the driving force transmission unit 70). Without being transmitted to the feed roller 25, the feed roller 25 is rotated forward by the reverse driving force of the transport motor 71.

[Second transmission unit 94]
The second transmission unit 94 transmits the driving force of the transport motor 71 transmitted through the switching mechanism 80 to the second transport roller 62. As shown in FIG. 7, the rotation of the second driven gear 84 is transmitted to the sun gear 94E through four intermediate gears 94A, 94B, 94C, 94D meshed in series. Since the sun gear 94E rotates in the direction opposite to the rotation direction of the second driven gear 84, the sun gear 94E rotates in the direction opposite to the normal rotation and the reverse rotation of the first conveying roller 60.

  A support arm 94G is rotatably attached to the rotation shaft 94F of the sun gear 94E. A pendulum gear 94H is rotatably supported at the tip of the support arm 94G. The pendulum gear 94H meshes with the sun gear 94E. The pendulum gear 94H revolves around the sun gear 94E and contacts and separates from the transmission gear 94J while rotating in the forward and reverse directions along with the forward and reverse rotation of the sun gear 94E. The transmission gear 94J is attached to the second roller shaft 62A of the second transport roller 62 so as to be integrally rotatable.

  As shown in FIG. 7A, the pendulum gear 94H is separated from the transmission gear 97J when the forward driving force of the transport motor 71 is transmitted and the sun gear 94E rotates. That is, the second transmission unit 94 does not transmit the normal driving force of the transport motor 71 to the second roller shaft 62A. On the other hand, the pendulum gear 94H meshes with the transmission gear 97J when the reverse driving force of the transport motor 71 is transmitted and the sun gear 94E rotates. That is, the second transmission unit 94 reversely rotates the second roller shaft 62 </ b> A by the reverse driving force of the transport motor 71.

  In other words, the first transport roller 60 and the second transport roller 62 are rotated forward in conjunction with each other by the normal driving force of the transport motor 71 transmitted through the first transmission unit 72. Further, when the driving force transmission unit 70 is in the second state, the first conveyance roller 60 and the second conveyance roller 62 transmit the reverse driving force of the conveyance motor 71 transmitted through the first transmission unit 72 and the second transmission unit 94. To reversely rotate in conjunction. On the other hand, when the driving force transmission unit 70 is in the first state, the first conveying roller 60 is rotated reversely by the reverse driving force of the conveying motor 71, and the reverse driving force of the conveying motor 71 is not transmitted to the second conveying roller 62.

  Furthermore, in this embodiment, the reduction ratio of the second transmission unit 94 is set lower than that of the first transmission unit 72. Therefore, when the transport motor 71 is rotated forward in a state where the pendulum gear 94H and the transmission gear 94J are meshed, the pendulum gear 94H is not separated from the transmission gear 94J, and the driving force transmission unit 70 is locked. Therefore, in the present embodiment, when the first conveyance roller 60 and the second conveyance roller 62 are rotated forward, the driving force transmission unit 70 is set to the first state, and the first conveyance roller 60 and the second conveyance roller 62 are rotated in the reverse direction. In this case, the driving force transmission unit 70 needs to be in the second state.

[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 a program 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.

  A transport motor 71 and a carriage motor 103 are connected to the ASIC 135. The transport motor 71 and the carriage motor 103 are rotated forward or reverse by a drive signal generated by the ASIC 135. The control unit 130 generates a control signal based on the image data and outputs it to the recording head 39. The recording head 39 ejects ink from the nozzles 39A based on the control signal. The control unit 130 displays a message or animation on the display unit 16.

  The ASIC 135 is connected to a registration sensor 17, a rotary encoder 19, a media sensor 18, and a carriage sensor 38. For example, the control unit 130 determines the position of the paper 12 or the media tray 31 on the second conveyance path 34 based on the combination of the first detection signal output from the registration sensor 17 and the pulse signal output from the rotary encoder 19. Is detected. Further, the control unit 130 detects the boundary position between the media tray 31 and the recording medium 32 based on the signal level of the second detection signal output from the media sensor 18. Further, the control unit 130 detects the position of the carriage 40 (more specifically, the media sensor 18) based on the pulse signal output from the carriage sensor 38.

[Image Recording Process for Recording Medium 32]
With reference to FIG. 9 and FIG. 10, the image recording process in this embodiment will be described. This image recording process is executed by the CPU 131 of the control unit 130. The following processes may be executed by the CPU 131 reading out 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 the image recording process shown in FIG. 9 in response to obtaining a recording instruction for the recording medium 32. The control unit 130 records an image on the recording medium 32 supported by the media tray 31 by controlling the operations of the rollers, the carriage 40, and the recording head 39 according to the acquired recording instruction.

  First, the control unit 130 notifies that the media tray 31 is set on the tray guide 30 (S11). For example, a message “Please set the media tray on the tray guide” may be displayed on the display unit 16. Next, the control unit 130 waits until the second conveyance path 34 is in the separated state (S12: No). The separated state of the second conveyance path 34 is a state in which the first conveyance roller unit 54 and the second conveyance roller unit 55 are in the separation state and the platen 42 is disposed at the separation position.

  Next, in response to the second transport path 34 being in the separated state (S12: YesNo), the control unit 130 waits until obtaining a start instruction for starting execution of image recording on the recording medium 32 (S13). : No). And the control part 130 switches the driving force transmission part 70 to a 2nd state according to having acquired a start instruction | indication (S13: Yes) (S14).

  Specifically, the control unit 130 moves the switching lever 86 to the position of FIG. Thereby, a force for moving the moving gear 81 to the second position is applied to the moving gear 81. Then, the control unit 130 performs a forward / reverse operation in which the transport motor 71 is alternately rotated forward and reverse in a state where the carriage 40 is in contact with the switching lever 86. As a result, the driving force transmission unit 70 is in the second state in which the moving gear 81 is moved to the second position and the moving gear 81 and the second driven gear 84 are engaged. However, when the driving force transmission unit 70 is already in the second state, the process of step S14 is omitted.

  Next, the control unit 130 executes image recording preparation processing for the recording medium 32 (S15). The preparation process is a process in which the control unit 130 detects the position of the media tray 31 and the size of the recording medium 32. The preparation process includes a process of changing the state of the driving force transmission unit 70 and a process of rotating the transport motor 71 forward and backward at least once. Details of the preparation process will be described with reference to FIG.

  First, the control unit 130 executes end detection processing (S21). The end detection process is a process in which the control unit 130 detects the rear end position of the media tray 31 (refers to the “upstream end in the transport direction”). Specifically, the control unit 130 reverses the transport motor 71 in order to cause the first transport roller unit 54 and the second transport roller unit 55 to transport the media tray 31 in the reverse transport direction. Then, the control unit 130 detects the rear end position of the media tray 31 based on the first detection signal output from the registration sensor 17 in the process of setting the media tray 31 in the reverse conveyance direction.

  In addition, after the first detection signal is output from the registration sensor 17 in step S <b> 21, the control unit 130 continues transporting the media tray 31 in the reverse transport direction. Then, the control unit 130 stops the transport motor 71 in response to the media tray 31 being transported by a predetermined transport amount after the first detection signal is output from the registration sensor 17. The predetermined transport amount in step S21 corresponds to a distance necessary for causing the rear end of the media tray 31 to protrude from the rear opening 36. The control unit 130 can specify the transport amount in step S <b> 21 by the pulse signal output from the rotary encoder 19.

  In addition, the control unit 130 sets the count value of the number of pulse signals of the rotary encoder 19 to 0 when the first detection signal is output from the registration sensor 17 in the preparation process. The control unit 130 adds the number of pulse signals output from the rotary encoder 19 to the count value by causing the transport motor 71 to rotate forward. Further, the control unit 130 reverses the transport motor 71 to subtract the number of pulse signals output from the rotary encoder 19 from the count value. This count value is used to specify the position of the media tray 31.

  Next, the control unit 130 switches the driving force transmission unit 70 from the second state to the first state (S22). In order to carry the media tray 31 more accurately, the media tray 31 at the time of step S <b> 22 is sandwiched between both the first carrying roller unit 60 and the second carrying roller 62. Specifically, the control unit 130 moves the switching lever 86 to the position of FIG. Thereby, a force for moving the moving gear 81 from the second position to the first position is applied to the moving gear 81. Then, the control unit 130 causes the carry motor 71 to perform forward / reverse operation. Accordingly, the driving force transmission unit 70 is in the first state in which the moving gear 81 is moved to the first position and the moving gear 81 and the first driven gear 83 are engaged.

  Here, the second conveyance roller 62 rotates forward by the normal rotation driving force of the conveyance motor 71 transmitted through the driving force transmission unit 70 in the first state, and the reverse driving force of the conveyance motor 71 is not transmitted. On the other hand, the second transport roller 62 is rotated forward and backward by the forward driving force and the reverse driving force of the transport motor 71 transmitted through the driving force transmission unit 70 in the second state. That is, the transport amount of the media tray 31 transported by the rotation of the second transport roller 62 during the forward / reverse operation varies depending on the transmission state of the driving force transmission unit 70 (that is, the position of the moving gear 81).

  However, it is not known at which timing during the forward / reverse operation of the transport motor 71 the engagement of the moving gear 81 and the second driven gear 84 is released and the moving gear 81 and the first driven gear 83 are engaged. . As a result, the position of the media tray 31 specified by the count value (hereinafter referred to as “assumed position”) and the actual position of the media tray 31 on the second transport path 34 (hereinafter referred to as “real position”). This will cause a deviation.

  Note that the actual position resulting from the execution of step S22 deviates from the assumed position in the transport direction. The amount of deviation in the transport direction of the position of the media tray 31 generated in step S22 is an example of a first amount of deviation. Further, such a displacement of the position of the media tray 31 can also occur in steps S27, S30, and S32 described later.

  The phenomenon that the actual position shifts in the conveyance direction with the forward / reverse operation mainly occurs when the driving force transmission unit 70 is in the first state. When the driving force transmission unit 70 is in the first state, the first transport roller 60 rotates in the reverse direction due to the reverse rotation of the transport motor 71 during the forward / reverse operation, and tries to transport the media tray 31 in the reverse transport direction. On the other hand, the second transport roller 62 does not reversely rotate due to the reverse rotation of the transport motor 71 during the forward / reverse operation, and thus becomes the resistance of the media tray 31 that tries to move in the reverse transport direction. Then, the actual position of the media tray 31 is shifted in the transport direction from the assumed position by this resistance.

  Next, the control part 130 performs a facing process (S23). The facing process is a process of causing the first reference line 32 </ b> A of the recording medium 32 to face the detection position of the media sensor 18. Specifically, the control unit 130 rotates the transport motor 71 in the forward direction so that the first transport roller unit 54 and the second transport roller unit 55 transport the media tray 31 in the transport direction. The control unit 130 stores in advance the length of the media tray 31 in the longitudinal direction, the position of the first reference line 32A in the longitudinal direction of the media tray 31, the distance between the registration sensor 17 and the media sensor 18, and the like. ing. Therefore, the control unit 130 can calculate the target rotation amount of the carry motor 71 in the face-to-face processing based on such information, the count value that is continuously counted, and the like. The rotary encoder 19 generates a pulse signal that accompanies the rotation of the first transport roller 60. That is, the “target rotation amount of the conveyance motor 71” in the present specification actually means the target rotation amount of the first conveyance roller 60.

  Next, the control unit 130 executes a process of measuring the width along the main scanning direction (width along the left-right direction 9) of the recording medium 32 supported by the media tray 31 (S24). The process of step S24 is an example of a width measurement process.

  In step S24, the control unit 130 moves the carriage 40 in the main scanning direction while irradiating the media sensor 18 with light. Next, the control unit 130 causes the second detection signal output from the media sensor 18 to change to a state where the second detection signal changes from a state above the threshold level to a state below the threshold level, and from a state below the threshold level to above the threshold level. The position changing to the state is detected as the boundary position between the media tray 31 and the recording medium 32. The control unit 130 measures the length of the recording medium 32 along the main scanning direction based on the number of pulse signals output from the carriage sensor 38 while the carriage 40 moves between the two boundary positions.

  Next, in response to the fact that the width of the recording medium 32 measured in step S24 is included in the threshold range (S25: Yes), the control unit 130 executes save processing (S26). The evacuation process is a process for causing the rear end of the recording medium 32 to reach the downstream side in the transport direction from the media sensor 18. Specifically, the control unit 130 rotates the transport motor 71 in the forward direction so that the first transport roller unit 54 and the second transport roller unit 55 transport the media tray 31 in the transport direction. The target rotation amount of the transport motor 71 in step S26 is determined in advance.

  Next, the control unit 130 switches the driving force transmission unit 70 from the first state to the second state (S27). Note that, similarly to the situation in step S22, the media tray 31 at the time of step S27 is sandwiched between both the first conveyance roller unit 60 and the second conveyance roller 62. The process in step S27 is common with the process in step S14 in FIG. Note that the actual position resulting from the execution of step S22 deviates from the assumed position in the transport direction. The deviation amount in the transport direction of the position of the media tray 31 generated in step S27 is an example of a second deviation amount.

  Next, the control unit 130 executes a process of measuring the length along the conveyance direction 16 (front-rear direction 8) of the recording medium 32 (length of the recording medium 32) (S28). The process of step S28 is an example of a length measurement process.

  Specifically, in step S28, the control unit 130 moves the carriage 40 so that the media sensor 18 is positioned on the extended line of the second reference line 32B. In step S28, the control unit 130 may move the carriage 40 so that the media sensor 18 is positioned at the center position of the two boundary positions in the left-right direction 9 detected in step S24. Further, the control unit 130 causes the media sensor 18 to emit light. Next, the control unit 130 reverses the conveyance motor 71 in order to cause the first conveyance roller unit 54 and the second conveyance roller unit 55 to convey the media tray 31 in the reverse conveyance direction. The control unit 130 calculates the target rotation amount of the transport motor 71 in step S28 based on the maximum value of the diameter of the recording medium 32 that can be supported by the media tray 31, the count value that is continuously counted, and the like. can do.

  Next, similarly to step S <b> 24, the control unit 130 detects a position where the second detection signal output from the media sensor 18 crosses the threshold level as a boundary position between the media tray 31 and the recording medium 32. Then, the control unit 130 measures the length of the recording medium 32 based on the number of pulse signals output from the rotary encoder 19 while the media tray 31 moves between these two boundary positions.

  Next, in response to the length of the recording medium 32 measured in step S28 being included in the threshold range (S29: Yes), the control unit 130 moves the driving force transmission unit 70 from the second state to the first state. (S30), and the preparation process ends. Note that, similarly to the situation in step S22, the media tray 31 at the time of step S30 is sandwiched by both the first conveyance roller unit 60 and the second conveyance roller 62. Since the process of step S30 is common to the process of step S22, the description thereof will be omitted. The amount of deviation in the transport direction of the position of the media tray 31 that occurs in step S30 is an example of a third amount of deviation.

  Further, the control unit 130 responds that the length of the recording medium 32 measured in step S28 is out of the threshold range, and the number of executions of step S28 is less than N (N is a natural number) (S29: No & S31: No), the driving force transmission unit 70 is switched from the second state to the first state (S32). Note that, similarly to the situation in step S22, the media tray 31 at the time of step S32 is sandwiched by both the first conveyance roller unit 60 and the second conveyance roller 62. Since the process of step S32 is common to the process of step S22, the description thereof will be omitted. The amount of deviation in the transport direction of the position of the media tray 31 that occurs in step S32 is an example of a fourth amount of deviation.

  Further, in response to the fact that the length of the recording medium 32 measured in step S28 is out of the threshold range and the number of executions of step S28 has reached N times (S29: No & S31: Yes), An error such as that the recording medium 32 is out of standard is notified (S33), and the image recording process is terminated. Further, in response to the fact that the width of the recording medium 32 measured in step S24 is out of the threshold range (S25: No), the control unit 130 notifies an error (S33) and ends the image recording process.

  Returning to FIG. 9, the control unit 130 corrects the target rotation amount of the transport motor 71 in a cueing process to be described later (S16). The cueing process is a process of causing the recording head 39 to face the area of the recording medium 32 on which an image is first recorded. In step S <b> 16, the control unit 130 calculates a target rotation amount of the transport motor 71 in the cueing process based on the image data included in the recording instruction and the count count value. Next, the control unit 130 corrects the target rotation amount with the first deviation amount, the second deviation amount, the third deviation amount, and the fourth deviation amount.

  The ROM 132 or the EEPROM 134 stores in advance a correction rotation amount for correcting each of the first deviation amount, the second deviation amount, the third deviation amount, and the fourth deviation amount. More specifically, the EEPROM 134 includes a first correction rotation amount for correcting the first deviation amount, a second correction rotation amount for correcting the second deviation amount, and a third correction amount for correcting the third deviation amount. A correction rotation amount and a fourth correction rotation amount for correcting the fourth shift amount are stored as the correction rotation amount. In the preparation process (S15), the positional deviation of the media tray 31 occurs in the transport direction. Therefore, the first correction rotation amount to the fourth correction rotation amount are values for correcting a shift occurring in the transport direction when the media tray 31 is transported. Each of these values is calculated by, for example, prior experiments or simulations.

  In addition, the control unit 130 counts the number of executions of steps S22, S27, S30, and S32 in the preparation process. As an example, if the length of the recording medium 32 detected by the control unit 130 in the first step S28 is within the threshold range, the number of executions of steps S22, S27, and S30 is 1, respectively. The number of executions of step S32 that is not executed is zero. As another example, if the length of the recording medium 32 detected by the control unit 130 in the second step S28 is within the threshold range, the number of executions of steps S22, S30, and S32 is 1 and the number of executions of step S27, respectively. Is 2.

  In step S16, the control unit 130 multiplies the number of executions of steps S22, S27, S30, and S32 by the correction rotation amount that corrects each deviation amount, and adds the result to the target rotation amount. Correct the amount. In many cases, the target rotation amount after correction is smaller than the target rotation amount before correction. The target rotation amount and each correction rotation amount are specified by the number of pulses of the rotary encoder 19, for example.

  Next, the control unit 130 performs cueing processing (S17). That is, in step S17, the control unit 130 causes the first conveyance roller unit 54 and the second conveyance roller unit 55 to convey the media tray 31 in the conveyance direction by the target rotation amount corrected in step S16. Rotate forward.

  Next, the control unit 130 executes a recording process (S18). In step S18, the control unit 130 causes the recording head 39 to eject ink from the nozzles 39A in the process of moving the carriage 40 in the main scanning direction, and the area of the recording medium 32 on which an image is recorded next is recorded on the recording head. The conveyance process to face 39 is executed alternately. The timing at which ink is ejected from the nozzles 39A is calculated from, for example, image data included in the recording instruction.

  Next, the control unit 130 executes a discharge process in response to the completion of image recording on the recording medium 32 (S19). In step S <b> 19, the control unit 130 causes the transport motor 71 to rotate forward until the rear end of the media tray 31 passes through the second transport roller unit 55.

[Effects of Embodiment]
According to the above embodiment, by correcting the target rotation amount of the transport motor 71 in the cueing process, the positional deviation of the recording medium 32 that occurs during the preparation process is corrected. Thereby, the positional deviation of the recorded image resulting from the switching of the driving force transmission state is suppressed.

  In the above-described embodiment, the example in which the target rotation amount of the transport motor 71 in the cueing process is corrected based on the shift amount of the media tray 31 generated in steps S22, S27, S30, and S32. Thereby, since the correction process needs to be executed only once, the processing amount of the control unit 130 is reduced. However, the correction timing of each shift amount is not limited to this.

  For example, the control unit 130 may correct the target rotation amount of the transport motor 71 in the face-to-face processing (S23) with a first deviation amount (in other words, a first correction rotation amount). Further, the control unit 130 may correct the target rotation amount of the transport motor 71 in the length measurement process (S28) with the second shift amount (in other words, the second correction rotation amount). Further, the control unit 130 may correct the target rotation amount of the transport motor 71 in the cueing process (S17) with a third shift amount (in other words, a third correction rotation amount). Furthermore, the control unit 130 may correct the target rotation amount of the transport motor 71 in the retreat process (S26) with a fourth shift amount (in other words, a fourth correction rotation amount).

  Here, since the deviation amount occurs in the conveyance direction, the target rotation amount of the conveyance motor 71 in the face-to-face process (S23), the cueing process (S17), and the retreat process (S26) after step S32 is: Correction is made so as to decrease by the corresponding shift amount. On the other hand, the target rotation amount of the conveyance motor 71 in the length measurement process (S28) is corrected so as to increase by the second deviation amount. According to the above configuration, the positional deviation of the media tray 31 caused by the state change of the driving force transmission unit 70 can be corrected by the processing immediately after that. As a result, the media tray 31 can reach the appropriate position in each process included in the preparation process.

  Further, the same value may be stored in the EEPROM 134 as a correction rotation amount for correcting each shift amount in each step. In this case, the control unit 130 corrects the target rotation amount in the cueing process (S17) with a value obtained by multiplying the total number of executions counted in steps S22, S27, S30, and S32 by the correction rotation amount. .

  In the above embodiment, an example of the preparation process for detecting the end position of the media tray 31 and the size of the recording medium 32 has been described. However, a specific example of the preparation process is not limited to this. That is, the preparation process only needs to include a forward / reverse operation for changing the state of the driving force transmission unit 70 once in order to detect the length and width of the recording medium 32.

  In addition, the first state and the second state of the driving force transmission unit 70 can be used, for example, when images are continuously recorded on a plurality of sheets 12. The following processing is executed, for example, in response to the control unit 130 obtaining a recording instruction for recording an image on the preceding sheet and the succeeding sheet supported by the feeding tray 20.

  First, the control unit 130 executes a feeding process for the preceding sheet. The feeding process is a process for causing the paper 12 supported on the feeding tray to reach the first transport roller unit 54. Therefore, the control unit 130 rotates the feeding roller 25 in the forward direction by setting the driving force transmission unit 70 in the first state and rotating the transport motor 71 in the reverse direction. Next, the control unit 130 performs a cueing process and a recording process on the preceding sheet that has reached the first conveyance roller unit 54. These processes are common to steps S17 and S18.

  Then, the control unit 130 executes the feeding process for the succeeding sheet supported by the feeding tray 20 when the recording process for the preceding sheet is completed and the preceding sheet has passed the first transport roller unit 54. To do. Here, by setting the driving force transmission unit 70 in the first state, the reverse driving force of the conveyance motor 71 is not transmitted to the second conveyance roller unit 55 that holds the preceding sheet. That is, the preceding sheet sandwiched between the second conveying roller portions 55 is not conveyed in the reverse conveying direction in the feeding process for the subsequent sheet.

  Next, the control unit 130 performs a cueing process and a recording process for subsequent sheets. Here, when the conveyance motor 71 is rotated forward in order to convey the subsequent sheet in the conveyance direction, the preceding sheet sandwiched by the second conveyance roller unit 55 is also conveyed in the conveyance direction. That is, the preceding sheet is conveyed in the conveying direction by the second conveying roller unit 55 that rotates forward in the cueing process and the recording process for the subsequent sheet. Then, in response to the completion of the recording process for the subsequent sheet, the control unit 130 executes a discharge process for the subsequent sheet. This process is common to step S19. As a result, the preceding sheet and the succeeding sheet are sequentially discharged to the discharge tray 21.

10 .... Machine 17 .... Registration sensor 18 .... Media sensor 24 .... Recording unit 34 .... Second transport path 40 .... Carriage 54 .... First Conveying roller unit 55 ... Second conveying roller unit 62 ... Second conveying roller 70 ... Driving force transmitting unit 71 ... Conveying motor 72 ... First transmitting unit 81 ... ..Movement gear 84... Second driven gear 94... Second transmission unit 103.

Claims (6)

A transport roller unit capable of forward rotation for transporting the recording medium in the transport direction and reverse rotation for transporting the recording medium in a reverse transport direction opposite to the transport direction;
A recording unit for recording an image on a recording medium conveyed by the conveyance roller unit;
A drive source capable of normal rotation and reverse rotation;
A driving force transmission unit capable of changing the state to a forward rotation state in which the transport roller unit is rotated forward by the forward rotation of the drive source, and a reverse rotation state in which the transport roller unit is rotated backward by the reverse rotation of the drive source;
A control unit, and
The driving force transmission unit is
A first transmission unit that transmits the forward driving force of the driving source to the transport roller unit, and the reverse driving force of the drive source is not transmitted to the transport roller unit;
A second transmission unit that transmits the reverse driving force of the drive source to the transport roller unit;
A moving gear that is disposed at the first position in the forward rotation state, is disposed at the second position in the reverse rotation state, and rotates when the forward / reverse rotation of the drive source is transmitted;
The reverse drive force of the drive source transmitted through the meshed movement gear is disposed at a position separated from the movable gear at the first position and meshed with the movable gear at the second position. A driven gear that transmits to the second transmission portion,
The control unit
In order to transport the recording medium to the transport roller unit in the transport direction and the reverse transport direction, the drive is performed in a state where a force for moving from one of the first position and the second position to the other is applied to the moving gear. A preparatory process for changing the state of the driving force transmission unit from one of the forward rotation state and the reverse rotation state to the other by a forward / reverse operation of rotating the source forward and backward, and driving the drive source;
After the preparation process, a cueing process for transporting the recording medium in the transport direction to the transport roller unit to a position facing the recording unit by driving the drive source;
A correction process for correcting the displacement of the position of the recording medium accompanying the forward / reverse operation in the preparation process by increasing or decreasing the amount of rotation of the drive source in the preparation process or the cueing process;
An image recording apparatus that performs a recording process of recording an image on the recording unit on a recording medium that faces the recording unit by the cueing process. A carriage motor capable of normal rotation and reverse rotation;
A first sensor that outputs to the control unit a first detection signal indicating that a recording medium is present at a detection position on the upstream side in the conveyance direction from the conveyance roller unit;
The recording part
A carriage that moves in the main scanning direction intersecting the transport direction by forward and reverse rotation of the carriage motor;
A second sensor that is mounted on the carriage and that outputs a second detection signal indicating that a recording medium is present at a position facing the carriage to the control unit;
The control unit
In the above preparation process,
An end portion for detecting a rear end position of the recording medium based on the detection signal output from the first sensor in the process of driving the driving source and conveying the recording medium to the conveying roller portion in the reverse conveying direction. Detection process,
A facing process in which the drive source is driven to a position where the recording medium faces the second sensor, and the recording roller is transported in the transport direction to the transport roller unit;
A width measurement process for measuring a width of the recording medium along the main scanning direction based on the second detection signal output from the second sensor in the process of moving the carriage in the main scanning direction. ,
The correction process corrects a first shift amount indicating the shift due to the forward / reverse operation for switching from the reverse rotation state to the first forward rotation state during the edge detection process and the facing process. 2. The image recording apparatus according to 1. The control unit
In the above preparation process,
A retreat process for driving the drive source to convey the recording medium in the conveying direction to the conveying roller unit until the rear end of the recording medium reaches the downstream side in the conveying direction from the second sensor;
Based on the second detection signal output from the second sensor in the process of driving the drive source and transporting the recording medium to the transport roller portion in the reverse transport direction, the length along the transport direction of the recording medium And a length measurement process for measuring
In the cueing process, the recording medium is transported in the transport direction to the transport roller unit to a position facing the recording unit by driving the drive source,
In the above correction process,
A second shift amount indicating the shift amount due to the forward / reverse operation for switching from the forward rotation state to the reverse rotation state during the retraction process and the length measurement process;
The third shift amount indicating the shift amount associated with the forward / reverse operation for switching from the reverse rotation state to the forward rotation state during the length measurement process and the cueing process is corrected. The image recording apparatus described.   The said control part performs the said evacuation process and the said length measurement process again in the said preparation process according to the length measured by the said length measurement process being out of a threshold value range. The image recording apparatus described.   In the correction process, the control unit corrects the target rotation amount of the drive source in the cueing process so as to decrease by the first shift amount, the second shift amount, and the third shift amount. Item 5. The image recording apparatus according to Item 3 or 4. In the correction process, the control unit
Correcting the target rotation amount of the drive source in the face-to-face processing to be reduced by the first deviation amount;
Correct the target rotation amount of the drive source in the length measurement process to be increased by the second deviation amount,
5. The image recording apparatus according to claim 3, wherein the target rotation amount of the drive source in the cueing process is corrected so as to decrease by the third shift amount. 6.

Images