Cleaning roller

摘要

A cleaning roller is used for electrostatically attracting residual toner left on a photoconductive drum. The cleaning roller includes a shaft and a member formed on the shaft to cover the shaft. The member has contact portions that lie in a cylindrical plane and a plurality of recesses that are formed in the member and bounded by the contact portions. The contact portions are in contact with the photoconductive drum to attract residual toner left on the photoconductive drum. The recesses hold therein the residual toner attracted to the contact portions. The recesses have openings that lie in the cylindrical plane such that a ratio of the areas of the contact portions to the areas of the openings is in the range from 3:7 to 1:1. The openings of the recesses have effective diameters in the range from 50 to 150 mu m if the toner particles have effective diameters in the range from 6 to 9 mu m. The cleaning roller includes a metal shaft and a resilient member formed on the metal shaft to cover the metal shaft. The resilient member has an electrical resistance in the range from 5x106 OMEGA to 5x109 OMEGA .