Patent ID: 6157799
Filing Date: 2000-12-05
Classification: G03G

Abstract:
A color image forming apparatus comprising:a plurality of image forming units, each image forming unit comprising a developing device for a different color and a photoconductive drum having driven coupling means;conveying means for switching the plurality of image forming units by moving them successively between an image forming position and a waiting position;photoconductive drum driving means removably engaging the driven coupling means of the image forming unit that is positioned in the image forming position and having one driving coupling means for coaxially rotating the photoconductive drum of the image forming unit positioned in the image forming position together as one body;transfer means for forming a color image on a transfer device by transferring and successively superimposing toner images formed with the developing device on the photoconductive drum onto the transfer device; andtransfer device driving means for driving the transfer device at a certain velocity;wherein, at a contact portion where the photoconductive drum positioned in the image forming position contacts the transfer device, a peripheral velocity of either the photoconductive drum or the transfer device during use is higher than a peripheral velocity of the other.