Fixing means for electrophotographic copier

摘要

A fixing means for an electrophotographic copier includes a first roller and a second roller which are compressed against each other and serve to fix toner images on an image transferring medium passed therebetween. A control means is programmed to operate the rollers such that the heating of the second roller is continued for a predetermined length of time or until the surface temperature of the second roller reaches a certain predetermined temperature level after the surface temperature of the first roller reaches another predetermined temperature level such that the second roller is prevented from cooling down suddenly after the fixing operation is started. In another aspect of the present invention, the size of the image transferring medium passed between the rollers is detected and the heaters for the rollers are controlled accordingly such that temperature variations on the roller surfaces can be reduced and hence the roller lifetimes can be improved.