Belt assembly, and a transfer unit and an image forming apparatus having the same

A belt assembly in an image forming apparatus, comprising:

• an intermediate transfer belt comprising a guiding rail disposed on a surface on a static side of the intermediate transfer belt and a reinforcing tape disposed on an opposite driving side on the surface of the intermediate transfer belt, wherein:
• the intermediate transfer belt is supported and rotated by an idle roller having two ends and a driving roller:
• the two ends of the idle roller are supported respectively by a first elastic member and a second elastic member each of which have different elastic coefficients, and:
• the idle roller further comprises a receiving part which supports the guiding rail, and the driving roller does not interfere with the guiding rail, and:
• a reinforcing tape escape groove is disposed on the driving roller to face and to receive the reinforcing tape and has a width and a depth equal to or greater than a width and a thickness, respectively, of the reinforcing tape.

A belt assembly in an image forming apparatus, comprising:

• an intermediate transfer belt comprising a guiding rail disposed on a first side of the intermediate transfer belt, wherein:
• the intermediate transfer belt is supported and rotated by an idle roller having two ends and a driving roller, further wherein:
• the two ends of the idle roller are respectively supported by a first elastic member and a second elastic member each of which have different elastic coefficients, and further wherein:
• the idle roller further comprises a receiving part to support and to receive the guiding rail, and further wherein:
• the driving roller does not interfere with the guiding rail, and a reinforcing tape is disposed on a second side of the intermediate transfer belt opposite the guiding rail on a surface of the intermediate transfer belt such that the idle roller and the driving roller do not interfere with each other.

A transfer unit in an image forming apparatus, the transfer unit comprising:

• a frame;
• and
• a belt assembly comprising:
• a driving roller and an idle roller which are rotatably mounted on the frame;
• and
• an intermediate transfer belt which is supported and rotated by the driving roller and the idle roller and comprises a guiding rail disposed on a side of the intermediate transfer belt,
• such that the driving roller does not interfere with the guiding rail.

An image forming apparatus, comprising:

• a photoconductive medium to form an electrostatic latent image thereon;
• a developing unit to form an image on the electrostatic latent image;
• and
• a transfer unit to receive developer disposed on the photoconductive medium to form an image,
• wherein the transfer unit comprises:
• a frame;
• and
• a belt assembly comprising:
• a driving roller and an idle roller which are rotatably mounted on the frame;
• and
• an intermediate transfer belt which is supported and rotated by the driving roller and the idle roller, and comprises a guiding rail disposed on a side of the intermediate transfer belt,
• wherein the driving roller does not interfere with the guiding rail.