Patent ID: 8983317
Filing Date: 2015-03-17
Classification: G03G

Abstract:
1. An image forming apparatus comprising: an image bearing member on which an image is formed; a charging unit configured to charge the image bearing member; a transfer unit configured to transfer the image formed on the image bearing member onto a transfer member; a first voltage application unit configured to apply a predetermined voltage to the charging unit so that the image bearing member becomes charged to a predetermined potential; a second voltage application unit configured to apply a voltage to the transfer unit; and a current detection unit configured to detect a current flowing to the image bearing member via the transfer unit when a voltage is applied to the transfer unit, wherein a surface potential of the image bearing member is determined based on information on a difference between a first voltage and a second voltage, the first voltage being applied from the second voltage application unit to the transfer unit when a value detected by the current detection unit, after the second voltage application unit applies a voltage to the transfer unit while changing the voltage from the predetermined voltage to a lower potential side, reaches a value indicating a start of discharge between the image bearing member and the transfer unit, and the second voltage being applied from the second voltage application unit to the transfer unit when a value detected by the current detection unit, after the second voltage application unit applies a voltage to the transfer unit while changing the voltage from the predetermined voltage to a higher potential side, reaches a value indicating the start of discharge between the image bearing member and the transfer unit.