Image forming apparatus

An image forming apparatus comprising:

• an image carrying member on a surface of which a photosensitive layer is formed;
• a charging member which makes contact with the surface of the image carrying member and electrostatically charges the image carrying member;
• an exposing device which scans, while exposing to light, the surface of the image carrying member electrostatically charged by the charging member to form an electrostatic latent image on the image carrying member;
• a destaticizer which removes electric charge remaining on the surface of the image carrying member;
• a high-voltage generation circuit which applies an oscillating voltage having a DC voltage and an AC voltage superimposed on each other to the charging member;
• a current detector which detects a charging current that passes between the charging member and the image carrying member;
• and
• a controller which controls the high-voltage generation circuit, wherein
• the controller is configured to execute a contamination state check mode including:
• a potential saturation step where, when no image is being formed, a surface potential of the image carrying member is saturated by applying the DC voltage alone to the charging member and stopping a drive of the destaticizer;
• an exposure step where the image carrying member of which the surface potential is saturated in the potential saturation step is exposed to light in an exposure pattern extending continuously over an entire area thereof in a main scanning direction while being displaced at a constant rate in a sub-scanning direction by the exposing device;
• and
• a current detection step where the charging current that passes while the exposure pattern formed on the surface of the image carrying member in the exposure step passes through the charging member is detected by the current detector,
• the contamination state check mode being a mode in which a contamination state of the charging member in the main scanning direction is checked based on the charging current detected in the current detection step.