Image forming apparatus capable of temporarily breaking the contact between the developer and the photosensitive drum with use of electric field

摘要

An image forming apparatus includes an image bearing member for bearing an electrostatic latent image; a first developing device for developing the electrostatic latent image on the image bearing member; a second developing device, faced to the image bearing member and having a movable developer carrying member for carrying toner and carrier, for effecting development after a first developed image provided by the first developing device passes through a position where the developer carrying member is faced to the image bearing member; and a preventing device for forming an alternating electric field between the developer carrying member and the image bearing member, while the second developing device is at reset to prevent the carrier of the second developing device from rubbing the first developed image.