Patent ID: 8254807

Claim:
A developing device comprising: a developer cartridge configured to accommodate a developer; and a developing unit to which the developer cartridge is configured to be detachably attached, wherein: the developing unit includes: a developing frame; a developer bearing member supported to the developing frame and being configured to bear the developer; a first guide fixed to the developing frame; and a second guide supported to the developing frame so as to be movable with respect to the developing frame between a first position where the second guide is continuous with the first guide and a second position where a continuous state of the second guide with the first guide is interrupted; the developer cartridge includes: a developer frame configured to accommodate the developer; and a first guided member supported to the developer frame so as to be movable with respect to the developer frame; the first guide and the second guide, when at the first position, are configured to guide the first guided member of the developer cartridge in the course of attaching the developer cartridge to or detaching the developer cartridge from the developing unit; and when an attachment of the developer cartridge to the developing unit is complete, the first guided member is received by the first guide, and the second guide is at the second position.