A driving device includes a motor, a drive gear, a swing gear, a first gear member, a second gear member, a frame, and a bracket. The swing gear can swing between a first position engaging with the first gear member and a second position engaging with the second gear member. The bracket has a slide hole including a pair of contact parts having an arc shape, and an arc hole part for connecting the pair of contact parts with a first sliding surface farther from the drive gear and a second sliding surface nearer to the drive gear. The first sliding surface has a shape retracting to the opposite side to the rotation shaft from tangential lines of the rotation shaft contacting with the contact parts, which are parallel to pressure angle directions between the drive gear and the swing gear, or a shape coinciding with the tangential lines.

An assembly comprises at least first and second transmission links. Each transmission link controls movement of a respective element coupled to a first side of the transmission link, under control of a common drive source coupled to a second side of the transmission link. A synchronizing unit is interposed between the first side and the second side of each transmission link, to synchronize movement of the respective elements by the common drive source.

A printer includes a head unit and a platen unit. The head unit includes a print head. The platen unit includes a platen roller, a support, and a guide roller. The platen roller is rotatably supported on the support and configured to rotate to convey recording sheet. The guide roller includes a roller part, and the roller part is configured to rotate in contact with the recording sheet as the recording sheet is conveyed.

A printer includes a head unit and a platen unit. The head unit includes a print head. The platen unit includes a platen roller, a support, and a guide roller. The platen roller is rotatably supported on the support and configured to rotate to convey recording sheet. The guide roller includes a roller part, and the roller part is configured to rotate in contact with the recording sheet as the recording sheet is conveyed.

A media processing device includes: a print head extending across a media path, and configured to apply indicia to media; a platen roller assembly adjacent to the print head, the print head configured to draw the media from a media supply along the media path travelling between the print head and the platen roller assembly, the platen roller assembly including: (i) a first platen roller extending across a first portion of a width of the media path, and (ii) a second platen roller coaxial with the first platen roller, and extending across a second portion of the width of the media path; a drive assembly coupled with the first and second platen rollers, the drive assembly configured to selectively drive rotation of either or both of the first and second platen rollers.

A recording apparatus includes a recording head that performs recording; a feeding roller that feeds out a medium that has been set, a transport roller that transports the medium fed out by the feeding roller toward a facing position facing the recording head; an auxiliary roller that is provided between the feeding roller and the transport roller and that assists in the transport of the medium; a motor that generates a driving force; and a drive train that is configured to transmit the driving force of the motor to the auxiliary roller and the transport roller.

A recording apparatus includes a recording head that performs recording; a feeding roller that feeds out a medium that has been set, a transport roller that transports the medium fed out by the feeding roller toward a facing position facing the recording head; an auxiliary roller that is provided between the feeding roller and the transport roller and that assists in the transport of the medium; a motor that generates a driving force; and a drive train that is configured to transmit the driving force of the motor to the auxiliary roller and the transport roller.

A power supply apparatus comprises: a first power supply line; a second power supply line; a connection unit connecting the first and second power supply line and capable of operating in either a first operation mode in which power transmission between the first and second power supply lines is possible or a second operation mode in which power transmission is not possible; an electric discharge unit connected to the second power supply line and capable of operating in either a third operation mode in which a voltage of the second power supply line is dropped or a fourth operation mode in which the voltage is not dropped; a voltage monitoring unit to monitor the voltage of the second power supply line; and a control unit to control operation of the connection unit and the electric discharge unit.

A power supply apparatus comprises: a first power supply line; a second power supply line; a connection unit connecting the first and second power supply line and capable of operating in either a first operation mode in which power transmission between the first and second power supply lines is possible or a second operation mode in which power transmission is not possible; an electric discharge unit connected to the second power supply line and capable of operating in either a third operation mode in which a voltage of the second power supply line is dropped or a fourth operation mode in which the voltage is not dropped; a voltage monitoring unit to monitor the voltage of the second power supply line; and a control unit to control operation of the connection unit and the electric discharge unit.

A motor control device includes a motor driver and a control unit. The motor driver supplies a drive current to a stepping motor. The control unit is configured to control the motor driver to start a supply of the drive current to the stepping motor in response to a start instruction, and increase the drive current to the stepping motor from zero to a predetermined current value stepwise over a predetermined time period.