Developing device, process cartridge and image forming apparatus

A developing device comprising:

• a developer bearing member configured to bear developer;
• a developing flame configured to accommodate developer to be borne by the developer bearing member and rotatably support the developer bearing member;
• a supporting portion including a fixed end fixed to the developing frame and a free end extending from the fixed end to the upstream side in the rotation direction of the developer bearing member;
• and
• a regulating portion provided at the free end of the supporting portion and configured to regulate the thickness of the developer borne on the developer bearing member by contacting with the developer bearing member,
• wherein the regulating portion includes
• a first contact portion contacting the developer bearing member,
• a second contact portion contacting the developer bearing member on the downstream side of the first contact portion in the rotation direction of the developer bearing member,
• a first opposed surface portion apart from and opposed to the developer bearing member on the upstream side of the first contact portion in the rotation direction of the developer bearing member, and
• a second opposed surface portion apart from and opposed to the developer bearing member on the downstream side of the first contact portion and on the upstream side of the second contact portion in the rotation direction of the developer bearing member, and
• wherein when, in a plane orthogonal to the rotation axis direction of the developer bearing member, the fixed end and the free end of the supporting member are connected by an imaginary straight line, a contact position where the first contact portion contacts the developer bearing member is located on the downstream side, in the rotation direction of the developer bearing member, of a point of contact of a tangent line parallel to the imaginary straight line with the outer periphery of the developer bearing member.