An image recording apparatus includes a roller pair for transporting a sheet, a recording head, and a controller. The controller determines a linefeed amount by which the sheet is transported by the roller pair between corresponding two adjacent passes of the recording head. The controller executes image recording on the sheet by alternately repeating a linefeed operation for rotating the roller pair by the determined linefeed amount to transport the sheet in a transport direction, and a pass recording operation in which the controller causes the roller pair to stop and the recording head to perform a pass and to record part of an image on the sheet. Upon determining that a linefeed operation would cause the sheet to travel past the roller pair while the roller pair is decelerating, replace for the linefeed operation a determined linefeed amount by an adjusted linefeed amount.

A one-way clutch includes a first rotator including an inner gear and configured to rotate on a first axis, a planetary gear configured to mesh with the inner gear and configured to rotate on a second axis that revolves around the first axis, a second rotator configured to rotate on the first axis and including a stopper configured to stop rotation of the planetary gear by engaging with the planetary gear, and an urging member configured to urge the planetary gear not to be brought in contact with the stopper in a state where the first rotator and the second rotator relatively rotate.

A medium transport device includes a feeding roller that feeds a recording medium, a transport roller that transports the recording medium toward a recording head, and a transport motor which is a common driving source for the feeding roller and the transport roller. The medium transport device includes a power transmission mechanism that transmits power of the transport motor to the feeding roller, and a control section that controls a current of the transport motor. The control section measures a current value flowing through the transport motor during driving as a measured current value, and adds a predetermined offset value to the measured current value to set a second limit value as a limit value of the current supplied to the transport motor.

A paper separation mechanism, comprising a separation roller assembly having a separation roller, a torque limiter connected to the separation roller, and a separation gear arranged between the separation roller and the torque limiter; a transmission gear assembly having a first transmission gear which is able to mesh or separate with the separation gear, a second transmission gear meshed with the first transmission gear, and a connecting part connected the first transmission gear and the second transmission gear; and a motor connected to the transmission gear assembly for applying forward or reverse torque; wherein when the motor is applying the forward torque, the connecting part rotates forward to mesh the first transmission gear with the separation gear; and when the motor is applying the reverse torque, the connecting part rotates reverse to separate the first transmission gear with the separation gear.

A sheet cassette that accommodates a recording sheet and is connected with a printer includes a first roller contacting a feed roller of the printer, a second roller contacting a recording sheet, a first gear and a second gear attached to a shaft of the first roller, a third gear and a fourth gear attached to a single shaft, and a fifth gear attached to a shaft of the second roller, wherein the first gear independently rotates relative to the first roller and the second gear, the feed gear of the printer engages with the first gear, the first gear engages with the third gear, the fourth gear rotates together with the third gear, the fourth gear engages with the fifth gear, and the second roller is rotated by rotation of the fifth gear.

A drive transmission device includes a rotatable driving member; a rotatable follower member, and an elastic member. The drive transmission device includes a first rotatable member and a second rotatable member. The first rotatable member includes first and second driving portions and a limiting portion. The second rotatable member includes a first driven portion, a second driven portion and a contact portion contacting the limiting portion. The second driving portion is adjacent to the limiting portion with respect to a rotational axis direction of the first rotatable member. The second driven portion is adjacent to the contact portion with respect to a rotational direction of the second rotatable member.

An image recording apparatus includes a roller pair for transporting a sheet, a recording head, and a controller. The controller determines a linefeed amount by which the sheet is transported by the roller pair between corresponding two adjacent passes of the recording head. The controller executes image recording on the sheet by alternately repeating a linefeed operation for rotating the roller pair by the determined linefeed amount to transport the sheet in a transport direction, and a pass recording operation in which the controller causes the roller pair to stop and the recording head to perform a pass and to record part of an image on the sheet. Upon determining that a linefeed operation would cause the sheet to travel past the roller pair while the roller pair is decelerating, replace for the linefeed operation a determined linefeed amount by an adjusted linefeed amount.

A sheet conveying device includes a sheet supporting portion, a first lever pivotable by contact with a sheet supported by the sheet supporting portion, a hook movable together with the first lever, a first cam configured to, when engaging the hook, stop rotating in a rotation direction of the first cam, a spring configured to urge the first cam in a rotation direction, a sector gear rotatable together with the first cam, a drive gear configured to, when engaging the sector gear, transmit a drive force to the sector gear, a feed roller rotatable in contact with the sheet, and a drive mechanism configured to receive a drive force from the sector gear and move one of the feed roller and the sheet supporting portion toward the other of the feed roller and the sheet supporting portion, to increase contact pressure between the feed roller and the sheet.

A clutch device includes a sector gear, a cam, an electromagnetic solenoid, a first lever, a second lever, a first spring, and a second spring. The cam includes a slide portion. The first lever engages with the electromagnetic solenoid and includes a first restricting portion. The second lever includes a hook and a second restricting portion. The first spring is configured to urge the second lever in a direction in which the first restricting portion and the second restricting portion contact each other. The second spring is configured to, when the electromagnetic solenoid is in a de-energized state, move the first lever. The slide portion of the cam has a surface configured to, when the electromagnetic solenoid is in an energized state, press the hook in a direction opposite to an urging direction of the first spring such that the second restricting portion is separated from the first restricting portion.

A sheet conveyance apparatus is configured to interlock a first transmission mechanism and a second transmission mechanism such that the second transmission mechanism switches a rotational driving direction of a reverse rotary member between a normal rotation direction and a reverse rotation direction with a delay with respect to the first transmission mechanism starting transmission of a rotational driving force such that a guide member pivots between a first pivot position and a second pivot position.