Patent ID: 8538314

Claim:
An image forming apparatus, comprising: an image forming unit to form an image on a printing medium; a discharging roller to receive the printing medium from a second feeding roller disposed between the discharging roller and the image forming unit, to rotate in a first direction to discharge the printing medium outside of the image forming apparatus after the image is formed on the printing medium, and to rotate in a second direction to transport the printing medium when the image forming apparatus operates in a duplex mode; a driving source to supply a rotation driving force in clockwise and counterclockwise directions to a discharging roller gear disposed at an end part of a rotation shaft of the discharging roller, the rotation driving force being supplied to the discharging roller gear through a second feeding roller gear disposed to an end part of a rotation shaft of the second feeding roller to the discharging roller gear, and to supply a rotation driving force to the image forming unit; a duplex transporter, disposed between the discharging roller and the image forming unit, to receive the printing medium from the discharging roller and to transport the printing medium toward the image forming unit; a swing gear unit to receive the rotation driving force in the clockwise and counterclockwise directions to transmit a driving force to the duplex transporter in a uniform rotation direction; and an aligning roller to receive the rotation driving force from the driving source to align the printing medium which is transported toward the image forming unit from the duplex transporter and then to transport the printing medium toward the image forming unit, wherein the swing gear unit further comprises a driving gear to receive the rotation driving force, and to transmit the rotation driving force to the swing gear unit, wherein the driving gear is disposed to an end part of a rotation shaft of the aligning roller, and wherein the driving source further supplies a rotation driving force to a pickup roller, a first feed roller, the second feed roller, a developing cartridge, the discharging roller, and the duplex transporter.