Provided are an image forming apparatus and an image forming method capable of coping with a medium exceeding a transport limit of a pair of rollers in image formation in which the medium is transported with the medium interposed between the pair of rollers. In a case where a medium exceeding a transport limit of first transport means to which medium transport using a first roller and a second roller is applied is used, second transport means is used to assist in the medium transport performed by the first transport means. The driving of second driving means for driving the second transport means is controlled using a driving signal applied to the driving control of the first driving means for driving the first transport means. Medium transport in which synchronization is taken between the first transport means and the second transport means is realized.

A tension controller includes a drive device configured to rotate a drive shaft, and a drive transmission device configured to transmit a rotation driving force of the drive shaft of the drive device to rotate a rotary shaft of a roll of a conveyance target medium. The drive transmission device including a tension applying device including a variable speed reducing device and a torque limiter, the variable speed reducing device and the torque limiter being disposed between the drive shaft of the drive device and the rotary shaft of the roll of the conveyance target medium. The variable speed reducing device of the tension applying device being configured to change a speed reduction ratio between the rotary shaft of the roll of the conveyance target medium and the torque limiter and to apply a tension force to the conveyance target medium.

A tension controller includes a drive device configured to rotate a drive shaft, and a drive transmission device configured to transmit a rotation driving force of the drive shaft of the drive device to rotate a rotary shaft of a roll of a conveyance target medium. The drive transmission device including a tension applying device including a variable speed reducing device and a torque limiter, the variable speed reducing device and the torque limiter being disposed between the drive shaft of the drive device and the rotary shaft of the roll of the conveyance target medium. The variable speed reducing device of the tension applying device being configured to change a speed reduction ratio between the rotary shaft of the roll of the conveyance target medium and the torque limiter and to apply a tension force to the conveyance target medium.

A bidirectional media supporting system includes a first and second rollers configured to rotate to feed media in forward and reverse feed modes; a first clutch bearing set, and a second clutch bearing set configured to engage with the first clutch bearing set; and a gear transmission assembly configured to transfer a driving force from the first roller to the second roller. A method for reversing direction of printing media includes advancing media while maintaining a rotational speed of a platen roller assembly above that of a feeding roller assembly; receiving a signal to reverse the direction of advancing media; and adjusting operation by reversing a direction of rotation of a transmission gear coupled to the feeding and platen roller assemblies, and by rotating the roller assemblies in an opposite direction, while maintaining the rotational speed of the platen roller assembly below that of the feeding roller assembly.

Provided are an image forming apparatus and an image forming method capable of coping with a medium exceeding a transport limit of a pair of rollers in image formation in which the medium is transported with the medium interposed between the pair of rollers. In a case where a medium exceeding a transport limit of first transport means to which medium transport using a first roller and a second roller is applied is used, second transport means is used to assist in the medium transport performed by the first transport means. The driving of second driving means for driving the second transport means is controlled using a driving signal applied to the driving control of the first driving means for driving the first transport means. Medium transport in which synchronization is taken between the first transport means and the second transport means is realized.

A bidirectional media supporting system includes a first and second rollers configured to rotate to feed media in forward and reverse feed modes; a first clutch bearing set, and a second clutch bearing set configured to engage with the first clutch bearing set; and a gear transmission assembly configured to transfer a driving force from the first roller to the second roller. A method for reversing direction of printing media includes advancing media while maintaining a rotational speed of a platen roller assembly above that of a feeding roller assembly; receiving a signal to reverse the direction of advancing media; and adjusting operation by reversing a direction of rotation of a transmission gear coupled to the feeding and platen roller assemblies, and by rotating the roller assemblies in an opposite direction, while maintaining the rotational speed of the platen roller assembly below that of the feeding roller assembly.