Multicolor image forming apparatus

A multicolor image forming apparatus for forming a multicolor toner image by superimposing monochromatic toner images that have been subjected to a primary transfer on an intermediate transfer belt and for subjecting the multicolor toner image to a secondary transfer to a printing medium in order to obtain a desired multicolor image, said multicolor image forming apparatus comprising:

• a driving roll and a plurality of driven rolls among which the intermediate transfer belt is stretched;
• first driving means for moving the intermediate transfer belt at a first speed for image formation;
• cleaning means which is pressed against one of said driven rolls via the intermediate transfer belt in order to clean a surface of the intermediate transfer belt;
• second driving means for rotating said one driven roll at a peripheral speed higher than the first speed;
• and
• clutch means which is included in said second driving means and adapted to connect power to said one driven roll when the load is increased by pressing said cleaning means against said one driven roll and to cut the transmission of the power to said one driven roll when the load is decreased by separating said cleaning means from said one driven roll.

A multicolor image forming apparatus for forming a multicolor toner image by superimposing monochromatic toner images that have been subjected to a primary transfer on an intermediate transfer belt and for subjecting the multicolor toner image to a secondary transfer to a printing medium in order to obtain a desired multicolor image, said multicolor image forming apparatus comprising:

• a driving roll and a plurality of driven rolls among which the intermediate transfer belt is stretched;
• first driving means for moving the intermediate transfer belt at a first speed for image formation;
• a load limiting driven roller disposed between two driven rolls, one of said driven rolls disposed at a secondary transfer position, and said load limiting roller kept in contact with the intermediate transfer belt stretched between said two driven rolls;
• cleaning means which is pressed against said load limiting driven roll via the intermediate transfer belt in order to clean a surface of the intermediate transfer belt;
• and
• second driving means for rotating said load limiting driven roll at a predetermined peripheral speed greater than the first speed by what is equivalent to a reduction in the speed of the intermediate transfer belt which is increased by press load derived from said cleaning means.