Patent ID: 7062209

Claim:
A transfer device comprising: plural transfer rollers supported so as to be upwardly and downwardly movable within a looped path of movement defined by an endless belt and opposed to respective of plural image carriers across a portion of the endless belt, the plural image carriers including plural image carriers for full-color image formation and an image carrier for monochromatic image formation, which are arranged in a row from an upstream side to a downstream side in a fixed direction of movement of the endless belt; a first path along which the endless belt is in contact with all the plural image carriers; a second path along which the endless belt is in contact with only the image carrier for monochromatic image formation; a third path along which the endless belt is spaced apart from all the plural image carriers; a transfer member moving mechanism for full-color image formation operative to reciprocate in a direction substantially parallel with the fixed direction of movement to raise and lower the transfer rollers opposed to respective of the image carriers for full-color image formation; a transfer member moving mechanism for monochromatic image formation operative to reciprocate in the direction substantially parallel with the fixed direction of movement to raise and lower the transfer roller opposed to the image carrier for monochromatic image formation; and first and second coaxial rotating cams having respective predetermined peripheral shapes, the first and second rotating cams being operative to cause respective of the transfer member moving mechanism for full-color image formation and the transfer member moving mechanism for monochromatic image formation to reciprocate as peripheries of respective of the first and second rotating cams displace with rotation, thereby switching the path of movement from one of the first to third paths to another selectively.