Patent ID: RE42797

Claim:
A developer replenishment apparatus for supplying a developer for replenishment to a developing apparatus to develop an electrostatic image formed on an image bearing member with the developer, comprising: a first developer container for accommodating said the developer for replenishment; a rotatable conveyance member disposed in the said first developer container to discharge said the developer for replenishment through a first an opening of said first developer container; a second developer container for receiving said the developer for replenishment discharged from said first opening of said first developer container ; a rotatable agitating member disposed in the said second developer container to agitate said the developer for replenishment; a rotatable conveyance screw disposed in said second developer container to discharge said the developer for replenishment through a second an opening of said second developer container toward said developing apparatus; and driving means which generates a rotational driving force; and a driving transmission mechanism which has a plurality of driving force transmission paths connected with said driving means and controls transmission of the rotational driving force to each of said rotatable conveyance member, said rotatable agitating member and said rotatable conveyance screw, by switching one of the driving force transmission paths to another of the driving force transmission paths, wherein said driving transmission mechanism has a path which does not transmit the rotational driving force to said rotatable conveyance screw in a case where the rotatable driving force is simultaneously transmitted to said rotatable conveyance member and said rotatable agitating member , wherein said driving transmission mechanism has a path which transmits the rotational driving force in a case where the rotational driving force is simultaneously transmitted to said rotatable conveyance screw and said rotatable agitating member, and wherein a rotation speed of said rotatable agitating member when said rotatable agitating member and said rotatable conveyance member are simultaneously rotated is lower than a rotation speed of said rotatable agitating member when said rotatable agitating member and said rotatable conveyance screw are simultaneously rotated .