Image forming apparatus acquiring a duration of overcharge

An image forming apparatus comprising:

• an image bearing body that bears a developer image to be transferred to a recording material;
• a charging member that charges the image bearing body;
• a transfer member that transfers a developer image formed by development, using a developer, of an electrostatic image formed by exposure of the charged image bearing body, from the image bearing body to a transferred body;
• a voltage applying portion that applies a voltage to each of the charging member and the transfer member;
• a current detecting portion that detects a current flowing through the transfer member;
• a preliminary exposing portion that exposes the image bearing body after the developer image is transferred and before the image bearing body is charged by the charging member;
• a setting portion that sets a value of a transfer voltage applied to the transfer member by the voltage applying portion during image formation;
• and
• an acquiring portion is provided which acquires a duration of an overcharged state occurring in an area of the image bearing body charged by the charging member after the image bearing body is exposed by the preliminary exposing portion,
• wherein an adjustment operation being performed before image formation is started and after the charging member charges the image bearing body, the adjustment operation involving the voltage applying portion applying a voltage with a predetermined adjustment voltage value to the transfer member and the setting portion setting the transfer voltage value based on a current value detected by the current detecting portion when the voltage applying portion applies the voltage, and
• wherein adjustment is made to an interval between a first timing when the preliminary exposing portion starts exposing the image bearing body before execution of the adjustment operation and a second timing when the voltage applying portion starts, during the subsequent adjustment operation, applying the voltage with the adjustment voltage value to the transfer member such that the second timing is later than a third timing when the duration acquired by the acquiring portion ends.