Abstract: In an image forming apparatus wherein a primary electrostatic latent image is formed on a photosensitive screen having a multitude of tiny openings therein and then an ion flow is modulated by the primary electrostatic latent image to thereby form a secondary electrostatic latent image on a chargeable member, the secondary electrostatic latent image formation occurs with both the screen bearing the primary electrostatic latent image thereon and the chargeable member being moved in the same direction and at the same velocity but with a corona discharge device for forming the secondary electrostatic latent image on the chargeable member being moved in the direction opposite to the direction of movement of the screen and chargeable member.