Image forming apparatus

An image forming apparatus comprising:

• a photosensitive member;
• a charging member for electrically charging said photosensitive member to a predetermined potential at a charging portion;
• a charging voltage source for applying a voltage to said charging member;
• an exposure device for exposing said photosensitive member to light to form an electrostatic image on said photosensitive member;
• a developing device, including a developing sleeve for carrying a toner, for supplying the toner to the electrostatic image on said photosensitive member to form a toner image;
• a developing voltage source for applying a developing voltage to said developing sleeve;
• a transfer member for forming a transfer portion where the toner image is transferred from said photosensitive member onto a transfer receiving member;
• a transfer voltage source for applying a voltage to said transfer member;
• a detecting member for detecting information on the voltage and a current when the voltage is applied to said transfer member;
• a setting portion for setting, on the basis of a detection result of said detecting member, a transfer voltage applied to said transfer member when the toner image is transferred from said photosensitive member onto the transfer receiving member at the transfer portion;
• and
• an adjusting portion for increasing a potential difference between the potential of said photosensitive member charged and the developing voltage so as to be large when an absolute value of the transfer voltage set by said setting portion is a first threshold or more and an absolute value of the current flowing at the time of application of the transfer voltage to said transfer member is a second threshold or less.