A developing device includes a developer carrying member for developing an electrostatic image with a developer, a developer container including a developing opening, and a developer supplying member for supplying the developer to a developing chamber through the developing opening. The developer supplying member includes a shaft member rotatably supported by the developer accommodating portion and a feeding member, wherein the feeding member includes a first feeding portion and a second feeding portion. The first feeding portion is provided in a downstream side, and the second feeding portion is provided in an upstream side with respect to a rotational direction of the shaft member.

A developing device includes: a developer carrying member; a developer container including a developer accommodating portion, a developing opening and a developing chamber; and a developer supplying member including a shaft member and a feeding member. The feeding member includes a first feeding portion having a length L1 and a radius R1, and includes a second feeding portion having a length L2 and a radius R2. When a length of the developing opening is L3, a shortest length from the developing opening to the rotation center of the shaft member is L4, and a length from the developer carrying member to the rotation center of the shaft member is L5, the following relationships are satisfied:

L1<L3<L2, and

L4<R1<L5.

A developing device includes a device housing, a developer holding member, and a supply member. The device housing contains developer. The developer holding member includes a magnetic field generating device and holds the developer. The supply member is rotated so as to lift the developer from below on a developer lifting side in a rotational direction thereof toward the developer holding member. The developing device has an exhaust passage that is provided along an outer circumference of the developer holding member and that allows air in the apparatus body to be exhausted therethrough. An opposite portion is defined on an opposite side to the developer lifting side in the rotational direction of the supply member. The developing device also includes a blocking member that intersects a tangent connecting the opposite portion to the inlet so as to block entrance of the developer into the exhaust passage.

A developing device includes a device housing, a developer holding member, and a supply member. The device housing contains developer. The developer holding member includes a magnetic field generating device and holds the developer. The supply member is rotated so as to lift the developer from below on a developer lifting side in a rotational direction thereof toward the developer holding member. The developing device has an exhaust passage that is provided along an outer circumference of the developer holding member and that allows air in the apparatus body to be exhausted therethrough. An opposite portion is defined on an opposite side to the developer lifting side in the rotational direction of the supply member. The developing device also includes a blocking member that intersects a tangent connecting the opposite portion to the inlet so as to block entrance of the developer into the exhaust passage.

A developing device includes a developer bearer to bear developer, a developer containing compartment to contain developer, and a developer conveyor including a shaft and disposed in the developer containing compartment. The developer bearer has magnetic poles adjacent to each other and identical in polarity, and the adjacent magnetic poles are disposed on a downward-rotation side where a surface of the developer bearer moves downward. The developer conveyor rotates to supply the developer to the surface of the developer bearer and collect the developer downstream, in a rotation direction of the developer bearer, from a developing range opposing a latent image bearer. The developing device further includes an inclined face disposed vertically below the adjacent magnetic poles, and the inclined face is inclined down toward the developer conveyor.

A developing device including a containing unit configured to be arranged below a supply member and contain a developer and a developer bearing member configured to bear the developer and develop an electrostatic latent image, further includes a supply member which is configured to supply the developer to the developer bearing member, to be arranged to form a nip portion between the supply member and the developer bearing member, and to rotate in a direction in which its surface moves from an upper end to a lower end of the nip portion, and a conveyance member which is configured to convey the developer contained in the containing unit onto the supply member.

A developing device including a containing unit configured to be arranged below a supply member and contain a developer and a developer bearing member configured to bear the developer and develop an electrostatic latent image, further includes a supply member which is configured to supply the developer to the developer bearing member, to be arranged to form a nip portion between the supply member and the developer bearing member, and to rotate in a direction in which its surface moves from an upper end to a lower end of the nip portion, and a conveyance member which is configured to convey the developer contained in the containing unit onto the supply member.