Image forming apparatus having brush and cleaning blade to remove toner remaining on image carrier

An image forming apparatus comprising:

• (a) an image carrier;
• (b) a charging unit which charges a surface of the image carrier;
• (c) a transfer unit which transfers a toner image formed on the image carrier onto a transfer material;
• (d) a brush which removes a toner remaining on the image carrier by rubbing the surface of the image carrier;
• (e) a cleaning blade provided downstream of the brush in a rotational direction of the image carrier, which removes the toner remaining on the image carrier;
• (f) a charging potential measuring sensor which measures a charging potential on the image carrier charged by the charging unit;
• (g) a memory unit which stores a data table in which a relation among the charging potential on the image carrier charged by the charging unit, a transfer current value of the transfer unit, and a stuck matter sticking to the image carrier, is stipulated;
• and
• (h) a controller which compares a measurement result by the charging potential measuring sensor with the transfer current value of the transfer unit in the data table, and corrects the transfer current value of the transfer unit or an image density according to a comparison result.