Patent ID: 9098062
Filing Date: 2015-08-04
Classification: G03G

Abstract:
1. A process cartridge detachably mountable to a main assembly of an image forming apparatus, said process cartridge comprising: an image bearing member on which an electrostatic image is to be formed; a developing roller, including a shaft member and an elastic layer therearound, for developing the electrostatic image while contacting a surface of said image bearing member at a peripheral velocity higher than a peripheral velocity of said image bearing member; a toner supplying roller contactable to said developing roller; a regulating member, contactable to said developing roller, for regulating a layer thickness of toner carried on a surface of said developing roller, wherein a length of said regulating member measured in a rotational axial direction of said developing roller is shorter than that of said developing roller; and a cleaning blade, contactable to said image bearing member, for cleaning said surface of said image bearing member; wherein said developing roller has a first region capable of carrying the toner regulated by said regulating member and a second region, outside of said first region, not carrying the toner, both of said first and second regions being contactable to said image bearing member, and said first and second regions being different with respect to the rotational axis direction, wherein said cleaning blade extends over said first and second regions when said cleaning blade is contacted to said image bearing member, wherein said shaft member has a first outer diameter in a region outside a first contact region between said regulating member and said developing roller, and a second outer diameter in a second contact region between said toner supplying roller and said developing roller, the first outer diameter being smaller than the second outer diameter, wherein, when said image bearing member and said developing roller rotate, said elastic layer deforms toward an upstream side with respect to the rotational direction of said developing roller by contacting said image bearing member, and wherein an amount of deformation of said elastic layer covering such a portion of said shaft member having the first outer diameter is larger than an amount of deformation of said elastic layer covering such a portion of said shaft member having the second outer diameter.