Patent ID: 7974555

Claim:
A development apparatus comprising: a developer tank that has first and second containers separated by a partition as to be adjacent to each other and respectively containing developer including toner and carrier; a developer carrying member that carries the developer contained in the developer tank and allows the developer to be adhered onto an image carrying member; a developer discharging mechanism that discharges a part of the developer contained in the developer tank; a developer replenishing portion formed in the developer tank and replenishing an amount of developer that is proportional to an amount of the developer discharged by the developer discharging mechanism to the developer tank; and a first developer transport member and a second developer transport member that extend in an axial direction from one tank side wall to an opposing tank side wall and are respectively contained in the first and the second containers, the first and a second developer transport members transport the developer while stirring the developer and pass the developer to each other at a first passing portion and a second passing portion and thereby cause the developer to circulate in the developer tank, the first passing portion being formed at a location of the partition adjacent to the developer discharging mechanism and the second passing portion being formed at a location of the partition away from the developer discharging mechanism, wherein the first and the second passing portions have configurations in which a transport force acting on the developer at the first passing portion is greater than the transport force acting on the developer at the second passing portion; and the partition, from the area having the first passing portion, extends unobstructed to one of the tank side walls that is farthest from the second passing portion.