Patent ID: 8666288

Claim:
A developing device, comprising: a developer carrier that carries, on its surface, a two-component developer including a toner and a magnetic carrier, moves the surface, and supplies the toner to a latent image on a surface of a latent image carrier in a developing area in which the developer carrier is opposed to the latent image carrier, thereby developing the latent image; a first conveying member that conveys the developer in a first conveying path that is formed in a developer storage unit that stores the developer to be supplied to the developer carrier; a second conveying member that conveys the developer in a second conveying path that is formed below the first conveying path in the developer storage unit; and a developer passing unit that conveys upward the developer which has reached at a conveying-direction posterior end of the second conveying path and passes the developer to the first conveying path, wherein the developer passing unit includes a plurality of pushing members that push up the developer by moving up, and when the pushing members push the developer, the developer can pass through from upper surfaces of the pushing members to lower surfaces of the pushing members, wherein the developer passing unit is a rotating member to which the pushing members are fixed and has a rotation shaft, and rotation of the rotating member on the rotation shaft changes vertical positions of the pushing members, wherein the first conveying member and the second conveying member are of screw members each having a rotation shaft, each member being helically provided with blades, and the first conveying member and the second conveying member are arranged so as to be approximately in parallel, a vertical position of the rotation shaft of the rotating member is at an approximately center position between vertical positions of axial directions of the first conveying member and the second conveying member, the rotation shaft of the rotating member is orthogonal to a virtual plane connecting the rotation shafts of the first conveying member and the second conveying member, and an outer diameter of the rotating member is larger than a distance between the shafts of the first conveying member and the second conveying member.