Image forming method and apparatus with means for reducing the accumulation of particle on a charging device

An image forming method and apparatus, wherein the charging amount that a charging device charges a photosensitive drum is controlled so as to reduce the charging amount in a period, except for the image forming period, than that during the image forming period. While the charging amount is reduced, the voltage applied to the charging device is controlled by chopping. Accordingly, mote adhesion onto the charging device and improper chopping can be effectively prevented or reduced. When print data is input from an outside source, the quantity of airflow generated by the fan is allowed to increase, and the printing operation starts after the quantity of airflow is increased. As sufficient airflow is generated inside the laser printer before the charging device starts to charge, motes and other objects existing in the laser printer can be ejected outside effectively. As a result, mote adhesion onto the charging device and improper charging can be prevented or reduced.