Patent ID: 6449449
Filing Date: 2002-09-10
Classification: G03G

Abstract:
A charging apparatus, comprising:a charge roller configured to adjoin to a photoconductive member so as to provide a charge to a surface of the photoconductive member, said charge roller comprising a plurality of roller layers including an elastic layer and a surface layer, said elastic layer having a resistivity such that a roller surface potential is raised by a charge movement, said resistivity of the elastic layer having a value such that a time period in which a charge moves within said elastic layer is sufficiently smaller than a time period in which an arbitrary point of said surface of said charge roller moves across a discharge region formed between said charge roller and the photoconductive member, wherein the resistivity of the elastic layer is less than 106 &OHgr;m and a resistivity of the surface layer is greater than 1010 &OHgr;m such that a charge potential of the surface of the photoconductive member is substantially constant even under different environmental conditions.