Patent ID: 6978100

Claim:
A developing cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, said developing cartridge comprising: a developing roller configured and positioned to develop an electrostatic latent image formed on an electrophotographic photosensitive member, having an elastic roller portion and a shaft portion supporting said elastic roller portion; a developer regulating member contactable to said elastic roller portion and configured and positioned to regulate an amount of the developer deposited on said elastic roller portion; and a protecting member including: a portion sandwiched between said elastic roller portion and said developer regulating member when said protecting member is demountably mounted between said developing roller and said developer regulating member; and a supporting portion configured and positioned to support said sandwiched portion, wherein said sandwiched portion has a hardness which is not less than a predetermined value and not more than the hardness of said elastic roller portion, and wherein said sandwiched portion has a thickness of 0.5 mm–2 mm, and said supporting portion has a thickness of approximately 150 μm.