Developing apparatus, process cartridge, and electrophotographic image forming apparatus including an elastic member preventing a gap between a developing agent carrier and a layer thickness limiter from changing, and an electrophotographic image forming apparatus detachably mounting such process cartridge

A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, comprising:

• an electrophotographic photosensitive drum;
• a developing agent carrier configured and positioned to supply a developing agent to said photosensitive drum to develop an electrostatic latent image formed on said photosensitive drum by use of the developing agent;
• a layer thickness limiting member configured and positioned to limit a layer thickness of the developing agent carried on a surface of said developing agent carrier, said layer thickness limiting member being disposed to form a gap with said developing agent carrier;
• a sealing member configured and positioned to restrict the developing agent from leaking out of an end in a longitudinal direction of said developing agent carrier;
• and
• an elastic member arranged to be in contact with said developing agent carrier to prevent the gap between said developing agent carrier and said layer thickness limiting member from changing upon bending of said developing agent carrier, wherein said elastic member is in contact with said developing agent carrier at an outer position in the longitudinal direction with respect to a position at which said sealing member is disposed.

An electrophotographic image forming apparatus for forming an image on a recording medium, comprising:

• (i) mounting means for detachably mounting a process cartridge including:
• an electrophotographic photosensitive drum;
• a developing agent carrier configured and positioned to supply a developing agent to the photosensitive drum to develop an electrostatic latent image formed on the photosensitive drum by use of the developing agent;
• a layer thickness limiting member configured and positioned to limit a layer thickness of the developing agent carried on a surface of the developing agent carrier, the layer thickness limiting member being disposed to form a gap with the developing agent carrier;
• a sealing member configured and positioned to restrict the developing agent from leaking out of an end in a longitudinal direction of the developing agent carrier;
• and
• an elastic member arranged to be in contact with the developing agent carrier to prevent the gap between the developing agent carrier and the layer thickness limiting member from changing, wherein the elastic member is in contact with the developing agent carrier at an outer position in the longitudinal direction with respect to a position at which the sealing member is disposed;
• and
• (ii) feeding means for feeding the recording medium.

An electrophotographic image forming apparatus for forming an image on a recording medium, comprising:

• an electrophotographic photosensitive drum;
• a developing agent carrier configured and positioned to supply a developing agent to said photosensitive drum to develop an electrostatic latent image formed on said photosensitive drum by use of the developing agent;
• a layer thickness limiting member configured and positioned to limit a layer thickness of the developing agent carried on a surface of said developing agent carrier, said layer thickness limiting member being disposed to form a gap with said developing agent carrier;
• a sealing member configured and positioned to restrict the developing agent from leaking out of an end in a longitudinal direction of said developing agent carrier;
• an elastic member arranged to be in contact with said developing agent carrier to prevent the gap between said developing agent carrier and said layer thickness limiting member from changing, wherein said elastic member contacts said developing agent carrier at an outer position in the longitudinal direction with respect to a position at which said sealing member is disposed;
• and
• feeding means for feeding the recording medium.