Developer replenishment apparatus

Abstract

The developer replenishment apparatus includes a first developer container for accommodating the developer for replenishment, a first conveyance member disposed in the first developer container to discharge the developer for replenishment through a first opening of the first developer container, a second developer container for receiving the developer for replenishment discharged from the first opening, an agitating member disposed in the second developer container to agitate the developer for replenishment, a second conveyance member disposed in the second developer container to discharge the developer for replenishment through a second opening of the second developer container toward the developing apparatus, and a driving device which does not drive the second conveyance member but drives the agitating member when driving the first conveyance member. The bulk density of the developer is thereby stabilized to make possible replenishment with the developer at high accuracy.

1. 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. 
 
     
     
       2. A developer replenishment apparatus according to  claim 1 , 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. 
     
     
       3. A developer replenishment apparatus according to  claim 1 , wherein said rotatable agitating member includes a first agitating member and a second agitating member each of which is arranged on each of both sides of said rotatable conveyance screw and causes said the developer for replenishment to circulate in said second developer container. 
     
     
       4. A developer replenishment apparatus according to  claim 2 , 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. 
     
     
       5. 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 the developer for replenishment;   a rotatable conveyance member disposed in said first developer container to discharge the developer for replenishment through an opening of said first developer container;   a second developer container for receiving the developer for replenishment discharged from said opening of said first developer container;   a rotatable agitating member disposed in said second developer container to agitate the developer for replenishment;   a rotatable conveyance screw disposed in said second developer container to discharge the developer for replenishment through an opening of said second developer container toward said developing apparatus;   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 by switching one of the driving force transmission paths to another of the driving force transmission paths,   wherein the plurality of driving force transmission paths includes a driving force transmission path which transmits a drive force to said rotatable agitating member without transmitting the drive force to said rotatable conveyance screw, when the drive force is transmitted to said rotatable conveyance member,   wherein the plurality of driving force transmission paths includes a path which transmits a drive force 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.   
     
     
       6. A developer replenishment apparatus according to claim 5, wherein said rotatable agitating member includes a first agitating member and a second agitating member, and
 wherein each of the first agitating member and the second agitating member is arranged on each of both sides of said rotatable conveyance screw and causes the developer for replenishment to circulate in said second developer container.   
     
     
       7. A developer replenishment apparatus according to claim 5, wherein said driving means has a first driving source for respectively rotating and driving said rotatable conveyance member and said rotatable agitating member and a second driving source for respectively rotating and driving said rotatable conveyance screw and said rotatable agitating member.