Patent ID: 7742710

Claim:
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 developer; a first developer accommodating portion for accommodating the developer discharged from said developer container, said first developer accommodating portion being capable of accommodating an amount of the developer, which is larger than a first predetermined amount, wherein the first predetermined amount is larger than a capacity of said developer container; a discharging device for discharging the developer toward said first developer accommodating portion; a second developer accommodating portion for accommodating the developer discharged from said first developer accommodating portion, said second developer accommodating portion being capable of accommodating an amount of the developer, which is larger than a second predetermined amount; a first supplying device for supplying the developer in said first developer accommodating portion toward said second developer accommodating portion; a second supplying device for supplying the developer in said second developer accommodating portion toward said developing device; a first detecting device for detecting an amount of the developer in said first developer accommodating portion, wherein said first detecting device is capable of detecting whether or not the amount of the toner in said first developer accommodating portion is equal to or larger than the first predetermined amount; a second detecting device for detecting an amount of the developer in said second developer accommodating portion; and a controller for controlling, when the developer is accommodated in said developing container, said discharging device such that the 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 the 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 amount, 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.