Patent ID: 8688012

Claim:
A developing device, comprising: a developing part configured to include a developer carrier which is arranged in a vicinity of an image carrier, and which is rotatable for circulating a developer inside the developing part and for supplying the developer to the image carrier; a developer supply member which is rotatable and carries and supplies the developer to the developer carrier; and a developer collection member which collects the developer which is not used to develop an image; a developer stirring part configured to be arranged at a different position from a position of the developing part; a developer conveyance part configured to carry the developer by an air conveyance in a developer conveyance path from the developer stirring part to the developing part, in which the developer being circulated in the developing part returns to the developer stirring part through a developer ejection flow path; and a developer detection part configured to include an opening which communicates between the developer supply member and the developer collection member, to be arranged at a downstream side in a flow direction of the developer from the opening below and near the developer supply member, and to detect whether the developer exists in a vicinity of the developer supply member.