Image forming apparatus

An image forming apparatus comprising:

• an image bearing member on which an electrostatic image is to be formed;
• a developing device for developing the electrostatic image with a developer;
• a developer container detachably mountable to a mounting portion provided in a main assembly of the apparatus, for accommodating a supply of developer;
• a discharging device for discharging the supply of developer from said developer container mounted to said mounting portion to an outside of said developer container;
• a first developer accommodating portion for receiving the developer from said discharging device and for accommodating an amount of the developer which exceeds a first predetermined amount, wherein the first predetermined amount is larger than a capacity of said developer container;
• a first detecting device for detecting an amount of the developer in said first developer accommodating portion;
• a first supplying device for supplying the developer in said first developer accommodating portion to an outside of said first developer accommodating portion;
• a second developer accommodating portion for receiving the developer from said first supplying device and for accommodating an amount of the developer which exceeds a second predetermined amount;
• a second detecting device for detecting the amount of the developer in said second developer accommodating portion;
• a second supplying device for supplying the developer from said second developer accommodating portion toward said developing device;
• a controller for controlling, when the developer is accommodated in said developing container, said discharging device such that amount of the developer in said first developer accommodating portion is not less than the first predetermined amount, in accordance with a detection result of said first detecting device and such that such that amount of the developer in said second developer accommodating portion is not less than the second predetermined amount, in accordance with a detection result of said second detecting device, and for permitting, when said developing container is substantially empty, and the amount of the developer in said first developer accommodating portion is less than the first predetermined value, an image forming operation to continue until the amount of the developer in said second developer accommodating portion becomes less than the second predetermined amount.