Patent ID: 7574161

Claim:
A developer cartridge comprising: a developer storing portion in which a developer is stored; a developer supplying portion for supplying said developer to a main body of an image forming unit; an opening-and-closing member that opens and closes said developer supplying portion; an engaging portion engagable with a to-be-engaged portion formed on said main body of said image forming unit; and an operating member movable in first and second directions to operate said opening-and-closing member and to cause said engaging portion and said to-be-engaged portion to engage each other and to release the engagement therebetween, wherein, when said operating member is in a predetermined position, the engagement of said engaging member and said to-be-engaged member is released and said opening-and-closing member closes said developer supplying portion, wherein, when said operating member moves in said first direction from said predetermined position, said engaging portion engages said to-be-engaged portion, and said opening-and-closing member closes said developer supplying portion, and wherein, when said operating member moves in said second direction from said predetermined position, said engaging portion engages said to-be-engaged portion, and said opening-and-closing member opens said developer supplying portion.