Patent ID: 8626034

Claim:
A development device comprising: a developer container for containing two-component developer including toner and carrier; a developer bearer to carry by rotation the developer contained in the developer container to a development range facing a latent image bearer; a partition dividing at least partly the developer container into a supply compartment and a collecting compartment, the partition positioned with an end portion thereof facing a circumferential surface of the developer bearer on a cross section perpendicular to an axial direction of the developer bearer; a developer supply member disposed in the supply compartment to supply the developer to the developer bearer while transporting the developer in the axial direction of the developer bearer; and a developer collecting member disposed in the collecting compartment above the developer supply member, to receive the developer from the developer bearer while transporting the developer in the axial direction of the developer bearer, wherein an opening is formed in a downstream end portion of the partition in a developer conveyance direction of the developer collecting member to cause the developer to fall to the supply compartment, and a width of the opening in a direction perpendicular to the axial direction of the developer bearer increases toward downstream in the developer conveyance direction of the developer collecting member.