Developer conveyance apparatus and process cartridge

A process cartridge detachably attachable to an apparatus main body of an image forming apparatus, the process cartridge comprising:

• an image bearing member on which a latent image is formed;
• a developer bearing member configured to develop the latent image by using developer;
• a developer storage portion configured to store developer to be borne by the developer bearing member;
• a developer conveyance portion arranged inside the developer storage portion and configured to convey the developer through rotation along a rotation axis thereof;
• a supplying opening configured to supply the developer to an exterior of the developer storage portion, and
• a clutch configured to transmit a drive force to the developer conveyance portion, the clutch stopping or decelerating a rotation of the developer conveyance portion, when a requisite torque for rotating the developer conveyance portion exceeds a predetermined magnitude, by suppressing transmission of the drive force to the developer conveyance portion;
• wherein the developer storage portion includes:
• a first storage portion in which the developer conveyance portion is provided and having the supplying opening;
• a second storage portion;
• an upstream side opening configured to allow the first storage portion and the second storage portion to communicate with each other, the upstream side opening being provided on an upstream side of the developer storage portion in a developer conveyance direction in which the developer conveyance portion coveys the developer;
• and
• a downstream side opening configured to allow the first storage portion and the second storage portion to communicate with each other, the downstream side opening being provided on an downstream side of the developer storage portion in the developer conveyance direction,
• wherein when the developer conveyance portion rotates, the developer circulates between the first storage portion and the second storage portion through the upstream side opening and the downstream side opening, and,
• wherein the clutch is arranged inside the first storage portion, is provided on an upstream side of the developer conveyance portion in the developer conveyance direction, and is opposed to the upstream side opening.