Patent ID: 8670683

Claim:
An image forming apparatus comprising: a photoreceptor for bearing a toner image; a transfer body onto which the toner image borne by said photoreceptor is transferred; a drive section for driving said photoreceptor and said transfer body, respectively; and a control section for controlling said drive section so as to drive said photoreceptor and said transfer body at a predetermined driving speed, wherein said control section is configured, under a state in which said control section controls to drive said transfer body at said predetermined driving speed, to control to: a) drive said photoreceptor while changing the driving speed of said photoreceptor within a range of driving speeds between a low speed and a high speed, including said predetermined driving speed, b) extract torque characteristics of said photoreceptor under the control which includes the change of driving speed of said photoreceptor, and c) determine the driving speed of said photoreceptor based on the extracted torque characteristics, wherein said control section is configured to obtain an inflection point of the extracted torque characteristics, and determines a driving speed which corresponds to the inflection point as the driving speed of said photoreceptor.