Image forming apparatus

An image forming apparatus, comprising:

• a photoconductor including a photoconductive layer forming a surface for carrying an electrostatic latent image;
• a charging member arranged in contact with or in proximity to the surface;
• a voltage applier for charging the surface by applying an oscillating voltage obtained by superimposing a direct-current voltage and an alternating-current voltage to the charging member;
• a rubbing member arranged in contact with the surface to rub the surface;
• a process executor for executing a refresh process of causing the rubbing member to rub the surface for a predetermined time by supplying toner to the rubbing member;
• a current detector for detecting a current value of a current flowing from the charging member to the photoconductor;
• a characteristic deriver for deriving an electrical characteristic of discharge products adhering to the surface on the basis of the oscillating voltage applied to the charging member by the voltage applier and the current value;
• and
• a process controller for determining whether or not to cause the process executor to re-execute the refresh process according to the electrical characteristic when the refresh process is finished.