Image forming apparatus and image forming method having control of cleaning depending on number of transferred images

An image forming apparatus that forms an image using a plurality of photoconductor bodies, comprising:

• a cleanerless transfer belt configured to convey paper to the plurality of photo conductor bodies;
• a switching unit configured to switch on/off a cleaner for each of the photoconductor bodies, on the basis of whether a single mono-colored developing agent is adhered to the transfer belt or whether two or more mono-colored developing agents are adhered to the transfer belt;
• and
• a control unit configured to control a change of a transfer bias for each of the photoconductor bodies, when the switching unit switches on/off the cleaners.

An image forming method for an image forming apparatus that forms an image using a plurality of photoconductor bodies, the method comprising:

• providing a cleanerless transfer belt that conveys paper to the plurality of photoconductor bodies;
• switching on/off cleaners for each of the photoconductor bodies, on the basis of whether a single mono-colored developing agent is adhered to the transfer belt or whether two or more mono-colored developing agents are adhered to the transfer belt;
• and
• controlling a change of a transfer bias for each of the photoconductor bodies, when switching on/off the cleaners.