Image forming apparatus with constant current voltage control

摘要

An image forming apparatus includes an image bearing member; a transfer member for transferring an image from the image bearing member onto a transfer material by a nip formed between the image bearing member and the transfer member; control means for effecting a constant current control for the transfer member with a predetermined current when a non-image area of the image bearing member is at the nip, and for effecting a constant voltage control for the transfer member during image transfer operation on the basis of a voltage applied to the transfer member during the constant current control; wherein a higher one of a constant voltage control signal for controlling the voltage in the constant voltage control and a constant current control signal for controlling the current in the constant current control, is selected as an output signal to the transfer member.