Developing apparatus and process cartridge

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

• an electrophotographic photosensitive member;
• a developing frame;
• a developing device including;
• a developer carrying member for feeding a magnetic developer to develop a latent image formed on the electrophotographic photosensitive member with the developer, wherein a magnet is disposed in said developer carrying member;
• a magnetic seal member provided at each of one and the other longitudinal ends of said developer carrying member with a clearance from a peripheral surface of said developer carrying member to prevent leakage of the developer in a longitudinal direction of said developer carrying member;
• a developer regulating member provided contacted to the peripheral surface of said developer carrying member to prevent reentering of the developer having passed through a gap between said developer carrying member and said magnetic seal member, wherein said developer regulating member is disposed downstream of a position where the gap is provided in a rotational direction of said developer carrying member, and said developer regulating member is positioned relative to said developing frame, and wherein said developing frame is provided with a developer carrying member mounting portion for mounting said developer carrying member;
• and
• a developing blade for regulating an amount of the developer deposited on the peripheral surface of said developer carrying member,
• wherein said developing frame is provided with a positioning projection, and by fitting a hole in said developer regulating member around the projection, said developer regulating member is positioned relative to the developing frame.

A developing apparatus comprising:

• a developing frame;
• a developer carrying member for carrying a developer to a developing zone where an electrostatic image formed on an image bearing member is developed by the developer, said developer carrying member being supported on said developing frame;
• a sealing member having a sealing portion for sealing a longitudinal end of said developer carrying member to prevent leakage of the developer at the longitudinal end;
• a developing blade for regulating a thickness of the developer on said developer carrying member;
• and
• a developer regulating member, disposed so as to contact a surface of said developer carrying member to prevent the developer having passed through the sealing portion on said developer carrying member from reentering the sealing portion;
• wherein said developer regulating member is provided with a positioning portion which is positioned relative to said developing frame, wherein said positioning portion is in the form of a hole which is engaged with a projection provided in said developing frame.

A developing apparatus comprising:

• a developing frame;
• a developer carrying member for carrying a developer to a developing zone where an electrostatic image formed on an image bearing member is developed by the developer, said developer carrying member being supported on said developing frame;
• a sealing member having a sealing portion for sealing a longitudinal end of said developer carrying member to prevent leakage of the developer at the longitudinal end;
• a developing blade for regulating a thickness of the developer on said developer carrying member;
• and
• a developer regulating member, disposed so as to contact a surface of said developer carrying member to prevent the developer having passed through the sealing portion on said developer carrying member from reentering the sealing portion,
• where said developing frame is provided with a common positioning portion for positioning said developer regulating member and said developing blade relative to said developing frame.