Patent ID: 8670696

Claim:
A developing device usable with an image forming apparatus, the developing device comprising: a housing in which a developer receiving chamber is defined; a partition to divide the developer receiving chamber into a first developer receiving chamber and a second developer receiving chamber; and a first developer delivery member arranged in the second developer receiving chamber to deliver developer in a first direction, wherein the partition includes a developer supply port disposed at one end thereof to allow the developer to be supplied from the first developer receiving chamber to the second developer receiving chamber during operation of the developing device, at least one opening also to allow the developer to be supplied from the first developer receiving chamber to the second developer receiving chamber, the at least one opening being spaced apart from the developer supply port, and a shield to block between the first developer receiving chamber and the second developer receiving chamber at an upstream position of the first direction, the shield being disposed at an opposite end of the partition with respect to the developer supply port so as to isolate the two developer receiving chambers from each other.