Patent ID: 7251440

Claim:
A development apparatus, comprising: a housing including a developer supplying/collecting unit and a developer stirring unit arranged in a front-and-rear direction and a projecting portion, the developer supplying/collecting unit and the developer stirring unit together forming a circular passage for carrying a two-component developer including a toner and a carrier; a developer carrying member arranged at a front side portion of the developer supplying/collecting unit to face an image carrying member with respect to a development region; a developer supplying/collecting section for carrying the developer in a rotation axis direction, the developer supplying/collecting section arranged at a rear side portion of the developer supplying/collecting unit to face the developer carrying member and to extend along a rotation axis direction of the developer carrying member; a first developer stirring section and a second developer stirring section arranged in a front-and-rear direction in the developer stirring unit to face each other and to extend along a rotation axis direction of the developer supplying/collecting section, the first and second developer stirring sections having peripheries that rotate and move the developer from an upstream side to a downstream side in a first developer carrying direction in the developer stirring unit; and a toner supply opening formed above a position where the first and second developer stirring sections face each other in the projecting portion and at the upstream side in the first developer carrying direction in the developer stirring unit, wherein the first developer carrying direction in the developer stirring unit is substantially opposite to a second developer carrying direction in the developer supplying/collecting section, wherein an amount of the developer carried by the first and second developer stirring sections is equal to an amount of the developer carried by the developer supplying/collecting section, and wherein the projecting portion projects outwardly in an axial direction from an end portion of the developer carrying member and supports end portions of the developer supplying/collecting section and the first and second developer stirring sections.