Image recording apparatus

摘要

There is provided an image recording apparatus including: a main body with first and second transporting paths, a transporting roller pair, a recording portion, a reversal roller pair, a re-transporting roller pair, a transporting motor, first and second transmission mechanisms, and a controller. The second transmission mechanism has: a sun gear, an arm, a pendulum gear, and a gear row. The second transmission mechanism is configured to change a posture between a first posture and a second posture. The controller is configured to determine a position of the sheet, determine a size of the sheet, switch the rotation of the transporting motor under certain conditions, and increase the rotation amount of the transporting motor more for the case that the size of the sheet is determined to be not less than a transport distance than for the case that it is determined to be less than the transport distance.

主权项

1. An image recording apparatus configured to record an image on a sheet, comprising:
a main body including a first transporting path and a second transporting path formed therein, the first transporting path being a path through which the sheet is transported in a first transporting orientation, and the second transporting path being a path which branches from the first transporting path at a branch position and rejoins the first transporting path at a junction position on the upstream side to the branch position in the first transporting orientation and through which the sheet is transported in a second transporting orientation from the branch position toward the junction position; a transporting roller pair provided at the first transporting path on the downstream side from the junction position in the first transporting orientation, and configured to rotate in a normal rotation to transport the sheet on the first transporting path in the first transporting orientation and to rotate in a reverse rotation in the opposite orientation to the normal rotation; a recording portion provided at the first transporting path on the downstream side from the transporting roller pair in the first transporting orientation and on the upstream side to the branch position in the first transporting orientation to carry out image recording on the sheet transported by the transporting roller pair; a reversal roller pair provided at the first transporting path on the downstream side from the branch position in the first transporting orientation, and configured to rotate in a normal rotation to transport the sheet with the images recorded by the recording portion in the first transporting orientation and to rotate in a reverse rotation to transport the upstream end of the sheet as the anterior end in the first transporting orientation to the second transporting path; a re-transporting roller pair provided at the second transporting path, and configured to rotate in a normal rotation to transport the sheet, transported to the second transporting path by the reversal roller pair, in the second transporting orientation; a transporting motor configured to rotate in a normal rotation and a reverse rotation; a first transmission mechanism configured to transmit one of the normal rotation and the reverse rotation of the transporting motor to the transporting roller pair and the reversal roller pair to rotate normally, and configured to transmit the other of the normal rotation and reverse rotation of the transporting motor to the transporting roller pair and the reversal roller pair to rotate reversely; a second transmission mechanism configured to transmit the rotations of the transporting motor to the re-transporting roller pair to rotate normally; and a controller, wherein the second transmission mechanism includes: a sun gear configured to rotate in a first orientation by the normal rotation of the transporting motor, and to rotate in a second orientation opposite to the first orientation by the reverse rotation of the transporting motor; an arm supported to be revolvable relative to the sun gear; a pendulum gear rotatably supported by the arm to engage the sun gear, configured to revolve around the sun gear in the first orientation by the rotation of the sun gear in the first orientation, and to revolve around the sun gear in the second orientation by the rotation of the sun gear in the second orientation; and a gear row including a plurality of gears engaging each other to transmit the rotation of the sun gear to a driving axle of the re-transporting roller pair by engaging the pendulum gear which has revolved in the first orientation and in the second orientation, wherein the second transmission mechanism is configured to change posture between a first posture and a second posture, the first posture being a posture to transmit the rotation of the sun gear in the first orientation to the driving axle with the pendulum gear and an odd number of gears included in the gear row, and the second posture being a posture to transmit the rotation of the sun gear in the second orientation to the driving axle with the pendulum gear and an even number of gears included in the gear row, wherein the controller is configured to perform: determining a position of the sheet; determining a size of the sheet; switching the rotation of the transporting motor from one to the other between the normal rotation and the reverse rotation under a condition that it is determined that the sheet having passed through the second transporting path has reached the transporting roller pair; and increasing the rotation amount of the transporting motor more for the case that the size of the sheet is determined to be not less than a transport distance from the reversal roller pair to the transporting roller pair than for the case that it is determined to be less than the transport distance, in an edge-alignment operation to cause the anterior end of the sheet to reach a print starting position facing the recording portion.