This specification discloses an invention relating to the relationship between a latent image bearing member such as screen-like photosensitive medium and a corona discharger used to form a latent image on the latent image bearing member. More particularly, the corona discharger is divided into a plurality of dischargers so that when the sum of the length of the corona discharger for the formation of the latent image and the length of the latent image bearing member is greater than the length in the direction of movement of an endless support member supporting the latent image bearing member, the plurality of dischargers may selectively discharge corona in accordance with the rotational position of the latent image bearing member. By this, the latent image bearing member may be prevented from being dually charged and the length of the latent image bearing member may be minimized to contribute to reduction in size of the image formation apparatus.