Patent ID: 7187893
Filing Date: 2007-03-06
Classification: G03G

Abstract:
1. An image forming unit, comprising: a photoconductive drum; an intermediate transfer belt to which a toner image formed on the photoconductive drum is primarily transferred at a primary transfer position and which secondarily transfers the toner image onto a recording medium; and a primary transfer roller disposed at the primary transfer position so as to oppose the photoconductive drum through the intermediate transfer belt; wherein a loose apparent density, a shape factor SF- wherein a rotary speed of the photoconductive drum and a circulation speed of the intermediate transfer belt at the primary transfer position are different, the image forming unit further comprising: said secondary transfer roller electrifies said intermediate transfer belt during at least a portion of the time in which said secondary transfer roller comes in contact with said intermediate transfer belt, wherein the electrifying of said intermediate transfer belt begins when no image is being formed and when said secondary roller is in contact with said intermediate transfer belt, and said electrifying ends before said secondary transfer roller retracts from said intermediate transfer belt, and a hardness of said secondary transfer roller is harder by 10 degrees or more than a hardness of said primary transfer roller as measured by an Asker-C hardness meter.