Patent ID: 7957658

Claim:
An image forming apparatus capable of forming an image at a plurality of image forming speeds, said apparatus comprising: an image bearing member on which an electrostatic image is formed; a developing container that receives a developer; a developer carrying member that is arranged to be rotatable and conveys said developer so as to develop said electrostatic image; a developer feed member that is arranged in contact with said developer carrying member and to be rotatable, and feeds said developer to said developer carrying member; a detection device that detects an amount of developer in said developing container by detecting an electrostatic capacitance between said developer carrying member and said developer feed member; and a control unit that changes a rotational speed of said developer feed member into a plurality of rotational speeds including a plurality of image forming rotational speeds corresponding to the plurality of image forming speeds, wherein said control unit controls the rotational speed of said developer feed member prior to the execution of a detection operation of said detection device so as to be faster than the slowest rotational speed of the plurality of image forming rotational speeds.