Patent ID: 7953331
Filing Date: 2011-05-31
Classification: G03G

Abstract:
1. A developing device comprising: a developer carrying device that carries a developer containing a toner and a carrier; a developer sleeve member that carries the developer, which is carried by the developer carrying device, to an area opposed to a latent-image bearing member according to surface movement of the developer sleeve member while bearing the developer on an endlessly-moving surface thereof, a latent image born on the latent-image bearing member being developed, wherein the developer carrying device includes: a developer carrying unit configured to carry the developer in a rotation axis direction while agitating the developer with rotation of an agitating and carrying member; and a toner-concentration detecting unit configured to detect a toner concentration in the developer carried in the developer carrying unit, wherein the agitating and carrying member includes: a screw member including a rotatably-supported rotation shaft member and a spiral blade protrudingly provided in a spiral shape on a peripheral surface of the rotation shaft member; and a reverse carrying blade that carries the developer in a direction opposite to a carrying direction of the spiral blade according to the rotation of the rotation shaft member is protrudingly provided in an area opposite to the pressing wall in the entire area in the rotation axis direction in the rotation shaft member, wherein the curved surface of the pressing wall is curved along a curvature of the spiral blade.