Image forming apparatus and transfer device thereof

An image forming apparatus for implementing a plurality of operating modes, comprising:

• a plurality of photosensitive bodies;
• a transfer belt configured to face the plurality of photosensitive bodies;
• a plurality of transfer units, each transfer unit including a transfer roller arranged to support an inner peripheral surface of the transfer belt at a position corresponding to an associated one of the photosensitive bodies and an elastic member configured to press the transfer roller to the corresponding photosensitive body;
• a slider configured to reciprocally move in a first direction;
• a drive unit configured to drive the slider;
• and
• an elastic unit configured to elastically bias one of the plurality of transfer units to separate the transfer roller of the one of the plurality of transfer units from the corresponding photosensitive body,
• wherein, when the image forming apparatus is in a first operating mode, the slider is configured to separate at least one of the transfer rollers from the corresponding photosensitive body through linear movement of the transfer roller in a second direction, and
• wherein, when the image forming apparatus is in a second operating mode, the slider is configured to press one of the plurality of transfer units so that the transfer roller of the one of the plurality of transfer units presses the corresponding photosensitive body.

A transfer device mountable in an image forming apparatus having first to fourth photosensitive bodies, the transfer device comprising:

• a supporting frame;
• a transfer belt configured to transfer an image formed on at least one of the first to fourth photosensitive bodies to a printing medium;
• a first transfer unit comprising a first roller frame supported by the supporting frame, a first transfer roller movably mounted to the first roller frame and an elastic member configured to press the first transfer roller toward the first photosensitive body;
• a second transfer unit comprising a second roller frame supported by the supporting frame, a second transfer roller movably mounted to the second roller frame and an elastic member configured to press the second transfer roller toward the second photosensitive body;
• a third transfer unit comprising a third roller frame rotatably mounted to the supporting frame and a third transfer roller mounted to the third roller frame to correspond to the third photosensitive body;
• a slider mounted to the supporting frame configured to move in a linear direction and configured to move the first transfer roller, the second transfer roller, and the third roller;
• and
• a drive unit configured to drive the slider.