Image-forming apparatus which forms images by using a developer

An image-forming apparatus comprising:

• a rotatable photoreceptor;
• charging means for charging the surface of the photoreceptor to a predetermined electric potential by means of corona discharging, the charging means being provided with a control electrode for controlling the quantity of corona ions that are allowed to reach the photoreceptor from a discharging electrode;
• latent image forming means for forming an electrostatic latent image on the photoreceptor that has been charged by the charging means by means of light irradiation;
• developing means for developing the electrostatic latent image by using a developer;
• and
• control voltage supply means which supplies a control voltage to the control electrode and which, upon allowing the photoreceptor surface electric potential to rise to the predetermined electric potential, during a non-image-forming period in which the photoreceptor is in rotation and no developing operation is carried out by the developing means, first supplies a low voltage bias as the control voltage so as to allow the photoreceptor surface to rise to a predetermined low electric potential, and then supplies a control voltage on the high voltage side.