Abstract: In an image forming apparatus having an image forming portion for forming an image on an image bearing member, a transferring portion provided with a transferring member capable of contacting with the image bearing member and a voltage applying portion for applying a voltage to the transferring member, and for electrostatically transferring the image on the image bearing member to a transferring medium, an electric current detecting portion for detecting an electric current flowing to the transferring member, and a control portion for performing an electric current detecting operation of detecting an electric current flowing when the voltage applying portion applies a predetermined voltage before an image transferring operation by the electric current detecting portion, and determining a transfer voltage applied to the transferring member during the image transferring operation on the basis of a result of the detection by the electric current detecting operation, the electric current detecting operation is pe

Abstract: In an image forming apparatus including a transfer apparatus which transfers a toner image formed on an image bearing member to a transfer material in a transfer portion and a guide member which guides the transfer material conveyed toward the transfer portion, a contact portion which comes into contact with the transfer material in the guide member is made of a material which is charged in the same polarity as toner by friction against the transfer material, and surface resistivity is not lower than 103 &OHgr;/square and not more than 1011 &OHgr;/sq.

Abstract: In an image forming apparatus having an image forming portion for forming an image on an image bearing member, a transferring portion provided with a transferring member capable of contacting with the image bearing member and a voltage applying portion for applying a voltage to the transferring member, and for electrostatically transferring the image on the image bearing member to a transferring medium, an electric current detecting portion for detecting an electric current flowing to the transferring member, and a control portion for performing an electric current detecting operation of detecting an electric current flowing when the voltage applying portion applies a predetermined voltage before an image transferring operation by the electric current detecting portion, and determining a transfer voltage applied to the transferring member during the image transferring operation on the basis of a result of the detection by the electric current detecting operation, the electric current detecting operation is pe